Sometimes I forget this happened, but it was so long ago, I copied this from a comment I made, but edited it a bit more here...
2003 - 2004?
Middle school or early high school (I don't understand well your USA system), one girl asked me to be her bf (maybe as a joke idk, her 2 friends were with her and basically told her to speak to me), i literally did a 180 and said bye, just wasn't into those things yet, only cared about watching Digimon and stuff. Typical nerd with thick glasses.
I always considered her physically unattractive but she was mostly a sweet heart with everyone, soft spoken, her mom was a religion teacher at our school.
Anyways, next year, hormones were doing its job I guess, she looked the same ugly duckling to me, but she also... I dunno, like something was calling me towards her. Funnily enough we got closer and for a short while became friends (since we got paired to do homework and stuff together a couple of times at school) and I though many years later, even to this day "man, I should've said yes, even if it was a prank or a short thing".
She became the girlfriend of the only "jock" (for you Americans) of the class about 3 months after my "rejection".
And that pretty much is my only type of relationship with the other sex. Never felt in love or got into a relationship. Even if the whole thing was a cruel prank to make fun of me, that would've been better than not experiencing anything and still dateless to this day. Especially since as a kid you don't need money, dress well, speak well or a car to really start dating (especially in a poor country like mine), meanwhile as an adult in mid 30s, in Europe is basically mandatory plus having great social skills.
Before you go full incel, are you doing anything that puts you in social situations? You don’t need to dress up beyond looking like a normal human that can take care of themself and maybe a single plant.
No I'm tired and don't fit in those places. Also stop trying to insult me. Again, taking care of yourself means being successful. I'm not.
Well, it's been twenty years since your closest brush with a relationship and you're still alive, so there is some amount of success going on in the taking care of yourself department.
I won't patronise you with the standard "find your people, hang in there!" comment. If it's really eating you up inside, you're going to have to take a few tiny steps towards society, because society won't make the first move. Otherwise just do whatever you want to do and quit looking into the past.
I feel like this works both ways. See Bowling Alone. Loneliness is a rising statistic, though unlike others I see isolation/escapism(/internet usage) as a symptom not a cause. I think money is a big reason.
Not sure about OP, but some of my perspective is from living in a tiny village in car-centric USA so there is not much social here for me, if anything at all. The "my people" are probably out there, perhaps even nearer than I think but that doesn't mean we'll ever have reason to know each other.
Suicide is painful, messy and scary. That's why.