Regret ain't what I thought it'd be

For a long time I never really understood myself it's like for most of my life if not all of it I've always just had some type of hate towards myself. Quarantine came around last year and It took me a movie to cry and man I still remember that sensation I got, I've had trouble crying for a LONG time and just that day alone I felt so good. I stopped crying because I didn't see the point I thought it'd be better to not cry since there are so many people who go through worse than me so what's the point? Now I see it in the opposite light. There was a girl in my school I was confused about what I felt towards her. For a long time, I thought I just found her to be a good person so that's why I cared about her. I never really knew or understood that I really liked her until quarantine. I knew she liked me, she practically said it and I did ask her out but she simply replied with "Was I serious" and my head took it as she's angry at me and I said I was joking. Quarantine happened and now I hate myself for not understanding myself or even trying to see what she would've said. For most of my life, it's been like I've been afraid of being accepted by people. A huge part of me wants to talk to her at the very least explain how much of a mess mentally I was then and hopefully be friends but It's been a year since then and I feel like if I brought up some of that or simply talked to her that I would be being selfish towards her. I'm trying not to think so negatively but I truly don't know what to do anymore. This regret I've had for a few months is just a pain and it's like every time I think about her I just hate myself. Not sure if forums are the best spot to ask questions as well but here it is I guess.