That's cause it was a one-time thing - and not the way it ALWAYS goes for you.
You've had other relationships. You know you can attract someone. You've done it before, and that means you know you can do it again. You know that you know what to do, and that when you are ready to try again, you can have confidence and faith that it will probably happen soon enough.
It's not like a brick wall for you, no results, no improvement, no sign at all that things are getting better at all, no sign at all that anything you think, say, or do is having any effect on the problem in any way, time after time, year after year. The countless years are part of it, but the worse part is the complete lack of indication that anything you're doing is working, or that there is anything you can do to help yourself. I get that feeling like a victim is unattractive especially for men, I get how and why that works, but when you're in this situation you really do feel like a victim of bad luck, like you have no power, because you're naturally inferior. Like again, with the dance guy - it was just that the guy wasn't right for you. It was never that you were inferior. You can have peace of mind that you're not.
And even if you don't want another relationship, that's the thing - it's you deciding, on your own, under your own power, that you don't want one. It's not being forced on you against your will.
And also, if you don't want another relationship, you can still say, "been there, done that". You can cross it off your list with the peace of mind that you've experienced it, you know what it's like, you don't have to worry about missing out anymore.
Again, I'm not yelling at you or blaming you for this. Just trying to explain it as clearly as I can, for anyone who might read this, because people really don't know. Most people don't worry about this that much, and take it for granted that they'll meet someone sometime and everything will be A-OK.
And I know you understand too. That's the thing, I've come to respect your willingness to see things from a perspective outside of your own experiences. Most people in your position wouldn't do that, they would just try to shame you by saying "work harder" while not really believing that you can or that it will make any difference even if you did, or they just double down on arrogance and act like they are just inherently superior beings, and people who don't have it as easy as them should just give up, know their place, and resign themselves to an unrewarding, unsatisfying, unfulfilling life of misery. "Not my problem", "got mine and that's all that matters, f you". This attitude seems like it's only increased lately.
The way that you are NOT like that, and are willing to listen and understand outside of your own perspective, really is a welcome breath of fresh air