I can certainly identify with you. I've been w/my b/f for 4 years and 5 months...
When I feel down about the relationship I'm in, I always think of the good times. Even though he might not always say the things I want him to, I think of the times when he was there to just listen to me cry my eyes out, or when we're hanging out- he could be with anyone at that very moment, but he's not- he's choosing that time to be with me. Or when he just calls me to say hello or leaves a funny voice mail... or even when he gets off his butt to get me a drink or something in the kitchen. Those little things add up...
There used to be a time when I didn't feel loved, wanted more affection, etc. but when I looked at things in perspective and think of all the things that my b/f has done for me and still does, it helps me realize that this relationship isn't bad at all.
Plus, there's all the history that we have together. No one knows me the way or to the extent that my b/f does. We can play off each others jokes, finish each others sentences... we simply understand each other.
Well aside from the good things, bad things can also add up and I can understand your worries.
Perhaps you could ask your b/f, "isn't it better to just not stress about the bad things and remember the good things?" and see how he responds. You could also start asking, "how was your day?" at the end of each day and initiate that conversation yourself.. and if he doesn't ask how your day was after telling about his day, just offer to talk about your day anyway.
I certainly remember when my b/f used to call me cute names and do all those little cutesy things, but that was earlier in the relationship; We have both matured a lot since then.
You two have been together for 3 years and 6 months. Although he might not talk about the future, I think just the fact that you two have been together for that long definitely shows his commitment to the relationship.
Anyway... sorry this was such a long post! lol I just want to help as much as possible because I know what it feels like. Hope this helped, at least a little bit.
Be strong!