i need advice

my girlfriend and i have been dating for 3 months and have had an on and off again thing for about a year. we are in love and for the most part things are perfect. both of us struggle with trust issues, anxiety, depression, etc. so we care about honestly a lot. when i first met her she was dating my best friend and they were only together for about a few months but they have remained good friends for years. about a month before we officially started dating her and my best friend made out. my best friend knew i liked her and she made the move because she was depressed and wasn’t thinking straight. i still cannot stop thinking about it and it drives me crazy. the thought of them together breaks my heart and ruins me for weeks. i told her how i feel and that she did nothing wrong but whenever we talk about it, it makes her feel horrible and depressed. i cant take it, im in love with her and don’t want to break up but idk if i can take it anymore. what should i do

All you need to do is decide whether continually rubbing this in her face will bring you both down or prompt her to break up with you. Leave her alone and focus on more intensive therapy for the "trust issues, anxiety, depression, etc"

You don't seem to be in the right frame of mind for a relationship right now particularly with her and especially since you are being almost abusive by bringing this up to her constantly, well knowing "it makes her feel horrible and depressed"..You're not the victim here, you are just not ready to date anyone at this point.

whenever we talk about it, it makes her feel horrible and depressed. i cant take it, im in love with her and don’t want to break up but idk if i can take it anymore.

She didn't do anything wrong. I don't understand why you are feeling this way. Why are you talking about this? Why do you enjoy punishing her?

It does not sound like you are ready to date anyone.

for the most part things are perfect

both of us struggle with trust issues

when i first met her she was dating my best friend. her and my best friend made out. she made the move because she was depressed and wasn’t thinking straight

In what way is "perfect for the most part"?

This has trouble written ALL OVER IT.

First you dated a girl that your best friend used to date (BAD NEWS!)

She made out with him just before dating you (BAD NEWS!)

You both struggle with trust issues towards each other (BAD NEWS!)

There is no relationship here.. just desperate using of each other for somethign other than love.

Leave. Walk. Move on.

Even if she and the best friend dated before, even a month before you started, if their relationship is done, you should have no problem with it. If its over, she should not feel horrible, but she does, and that’s where it becomes blurry to me. You said that she made the move because she wasn’t thinking straight. Then she will end up hurting you whether on purpose or not because of her impulsiveness. And as everyone said, you re not ready to date. If you are young, consider learning the ropes of relationships first, by reading up or getting tips from reliable friends or relatives. When I was young, couples went through courtship, very good learning experience on how to navigate the world of romance. Relationships seem simple from the outside until you are in one.