Why am I (21M) so single?

I’ve just turned 21 and the feelings of loneliness only get worse as the years go by. All my friends are getting into/have been in committed relationships, and I always see people from High school with partners, including the gay ones.

I feel like I’m not an ugly or unattractive person—I’ve been told I’m not. I try to be as self-aware and conscious of my actions as possible so not to be an unpleasant person. I go out frequently, put myself out there, use apps, meditate, do my childhood hobby (horse riding, which I love dearly), I work out, go to school and study, have a job, etc. I try to make myself as busy as possible and to invest in myself as much as I can.

At one point I even overworked myself (0 rest days a week physically or mentally) and ended up being so drained and feeling like I had accomplished nothing to try and occupy myself. In contrast, I have also sought out some therapy sessions. I deleted all social medias for weeks to stop myself from comparing to others. Yet through it all, the nagging feeling of wanting a Bf pushed through, and just stayed in my head.

I feel like I keep having crushes on men who wouldn’t like me back (straight or just are not interested in me if they are gay). I genuinely don’t know what to do at this point, and I’m so frustrated.