Batya33

My parents were long distance for 4 years when my dad went away for grad school but they'd been dating for years and were engaged -they married in their early 20s.  They saw each other maybe once a month.  It can work when there's already a serious and established LTR -my husband and I were long distance for a few years as well.  You've only been out with her a few times followed by her 2 week trip where it looks like she already met someone else.  It's not worth it to stay in touch -college will be a whole new world for her and I doubt she'll want to date local people for the periods of time she's home. I'm sorry.  

Here is a productive conversation -use I statements.
"I see you prioritize T when we are together to where I feel ignored by you and like I don't matter.  For example you are attentive to whether she needs another beer or needs anything and by contrast you are inattentive to me.  I feel disrespected by you when that happens and it happens often.  I deserve a partner who prioritizes me in those situations.  I can't speak for how anyone else would feel or react but those are my standards and what I expect."
The conversation then turns to him - see how he reacts.  If he begs for forgiveness and promises to change then it's up to you whether to give him another chance -you will know soon enough by his behavior.  Good luck.
(Also as much as Terrie is befriending you -she's enjoying the attention at your expense and I'm sure she knows it -and perhaps it's a turn on or neutral for her husband but if I were her husband....)

I think he was joking around -he asked you for your number so he can contact you and not just have to randomly run into you.  Unclear whether he wants to date you or be friends -if he calls you I'm sure you'll know soon enough.  

Oh ok.  Find a person who doesn't want to talk to any females other than you because there is always a risk that since he is a human being he might make friends with others and laugh with them and have close personal conversations as friends do.  Find a person who will prioritize your insecurities and be an open book -show you his phone every day and devices and prove to you that he spoke to no females other than in purely business conversations or maybe his mom or sister if that is ok with you.  Don't be surprised if you end up losing sexual attraction because it's a little bit like a mommy-son interaction (although also quite controlling for a mom and son -I don't control my son in that way).  
There are people who also believe that only the man and woman should laugh with each other and enjoy being around each other and no one else.  It's rare but if that's what you feel you need for your insecurities (meaning not because you care so much about the person -it's about you and your insecurities) then find that person -or get therapy to resolve these issues.  
Please know that the person who will put up with that likely will also want you to account for all your movements and interactions when you leave the house and will put restrictions on where you are allowed to go and who you are allowed to see to avoid the risk you might have a blast laughing with and getting to know a new person as a friend.
Does that sound fun, loving, and caring? I mean if it does go for it. He's not that guy.
For me personally it enhances a relationship when both people have close friendships outside of the relationship and have fun and do fun activities outside of the relationship -then come back home and share all the fun stories and perhaps introduce their partners to their new acquaintance or friend -or not.  It's pretty darn stifling and suffocating to feel restricted to having a great time only with one's partner.  For most people.  Especially it if's because of insecurities.  JMHO.  Good luck to you and you do you, ok?

She might have loving feelings for you and at the same time she is choosing this man just like you chose fear over her and took the risk that you would lose her in the meanwhile which you did.  Love is not enough.  What I would do is completely stay out of her life.  She knows how you feel.  In the future she might contact you, might be single again and might want to try again and at that point -if it happens -if you are still interested and available then you two can explore whether you two have changed enough so that this time you will choose commitment over fear.  
I got back together with my ex fiancee several years after our cancelled wedding.  I was scared momentarily when he asked me to try again.  I chose him over fear.  I did feel jitters at times because it's kind of normal when the first time was such a failure.  I chose him and our love and our commitment over those jitters which resolved. They were jitters -not core-shaking doubts. You felt scared because of overwhelmingly strong feelings.  You felt vulnerable apparently. 
It's fine that you chose fear over her and it's unfair to expect her to wait for you. But again I'd leave her 100% alone so you don't interfere in her new relationship and move on -who knows what can happen in the future?

How often does he take you out on dates he plans in advance? Have you met his friends and family? How often do you suggest activities for the two of you to do outside of his home? Does he cook for you? Take care of you when you're sick?  Are you two allowed to date other people? Why in the world are you having sex with someone and you don't feel comfortable asking him what he means when he says I need you?

No need to do anything aggressive. Rehearse in advance how you’re going to ask him out time  and place. Don’t text. Talk to him. “Hi - there’s this great movie /great museum exhibit/ concert / holiday light display/ new ice cream place - are you free on - day ?” Yes do that. Don’t expect him to plan something again - be polite since you declined and it’s your turn.  Then offer to treat him. 
my future husband and I met at work and he had to get up the courage to ask me for lunch.  He was very shy. He did it. Now we have a lovely family. It’s worth it 

So that's a lovely sentiment -sort of a good mantra- a goal post.  In your daily life get very specific and honest with yourself about what you want to see -what are you seeing and what is "as they are" to you -individually - commanding yourself abstractly to see things as they are is not as effective as dealing with basic common sense in every day situations. 
For example yesterday my 13 year old son threw away a fancy truffle I gave him as a treat for school because he thought he saw a classmate looking at it and he felt self-conscious.  He made up a story in his head that the classmate was critical of what he had in his backpack and that because of that he should get rid of it.  Even if the classmate was being critical -seeing things as they are -didn't mean he had to make up a story that this meant he should discard it so the classmate would approve.  That goes with dating too. 
So if a guy doesn't call you after a first meet or a first date, instead of seeing it as "he didn't call because he probably only wanted sex from me like all men," or "I shouldn't have told him I getting married in the future when he asked me what I was looking for - men don't want to get serious so that was dumb to say" perhaps see it as "it was a first meet, many first meets don't lead to first dates and there's no reason for me to take it personally."  That way you get to move on with a reasonably positive mindset and not with a jaded/bitter story in your head.  

I don't think you are a good person for her son to be around given your judgey comments about him and your lack of experience with teenagers or any children just makes it worse.  My son was criticized loudly by a cashier for crying and fussing while we waited for her to figure out how to do a refund.  My son was 9 months old.  It brought me to tears.  It's just as bad with a teenager and a single mom who is trying to be both mother and father. He doesn't need some guy around who doesn't like him and isn't married to his mom.  
Very thoughtful of you to help care for her given her leg injury.  Now that she's better move out and I wouldn't date her either because you don't seem to respect her either.  It's fine that you two are not a match but please don't subject an adolescent boy to this hostility and negative energy coming from you.  

It's not about whether it was one message or fifty.  If she wanted to go on a date with you she would want you to know that clearly so you wouldn't move on to other options.  

My sense is covid forced her to slow down and sit quietly with herself and then she knew things weren't right anymore.  She's using big words like "discover myself" so she doesn't bluntly say "I want to be free to socialize and potentially date others." 
My mom got married at age 21 and I know she discovered a lot about herself in the 62 years she was married and in the 5 years prior to that they dated/were engaged.  One of my nieces is in her mid 20s and a married mom of 3 - she is also working on discovering herself right now. 
I married at 42 and discovered a lot about myself and didn't need to look to date others or date others to do so. 
She wants to be back in the swing of things socially where she can answer to no one but herself and if some cute guy catches her eye she might consider flirting/dating without feeling like she's betraying you. 
People of all ages and stages of life outgrow relationships, realize it's not working.  I'm really sorry it hurts and avoiding contact is the best way to heal IMO.

I married at 42.  I married a man not a boy -date women not "good girls".  They were not all taken by a long shot.  I dated on and off for 24 years, stopped in 2005 at age 39.  I wasn't looking for a good boy or a "nice guy" -I was looking for the right match for me and part of that was becoming the right person to find the right person.  
Here is how I met potential good matches in my 30s -and I'll add in how some of my friends did. Many married in their 30s and 40s.
salsa dancing lessons, playing tennis, volunteering backstage at community theater, volunteering a homeless shelter, professional networking organizations, the gym, online dating sites (I did not date online ever -I met over a 100 men in person and exchanged a few messages and one phone call prior to meeting and not more -with rare exception), at work, through work, through set ups by:  former classmates, coworkers, neighbors, friends of friends (I set up lots of people too-it helps when you reciprocate).
At age 28 I moved 9 miles away to be right in a major city teeming with singles plus a 35 minute walk to work so I could maximize my search for a husband and hopefully eventual family.  It was expensive but well worth it.  
I did let some "good guys" go -one in particular in my early 20s - but I wasn't ready to be into someone like him.  I was more into the guy I was dating who was edgy, hot looking and as it turned out many years later after we'd broken up in tortured denial about his sexual orientation.  It happens - you're not in the right mindset, your goals are not aligned and even though you might have incredible chemistry years later (happened to me with my ex fiancee who I married 11 years after our cancelled wedding) - if it's not there at the time -it's just not.  Often it has to do with age, stage in life, personal growth.
Comparing yourself is a path I strongly advise not taking.  I have friends happily married since the 1980s when we were in our 20s, women who settled in their 30s and either got divorced or are unhappy, women who settled but act all smug married on Facebook cheerfully lying on social media when they're actually unhappy, women who married as my friend did in her 60s after being widowed and is incredibly happy to have reconnected with a high school sweetheart and married him, and my dear friend who was supposedly head over heels in her 20s, married and had multiple children, divorced many years later and tells me she was lying to herself and all of us and simply settled/wanted to be a married mom desperately. 
There are many long lasting happy marriages, even better than happy - but comparing yourself to those marriages -why? It's not  a race or competition.