I'm basically you in your 20s from what it sounds like. Even in my late teens I apparently also passed over lots of ladies who might have had a thing for me but I was too focused on the one girl that I had been infatuated with since I was 11 and only got over when I was 20. From 21 to 26 I had been pining over a different girl who came into my life only to get swept into focusing on someone else just a couple months ago only for THAT to die out too despite how close she seemed to being perfect for me. I have my regrets, but they're more about how getting my hopes up was a bad idea in the first place.
Since you're older than me, unfortunately I have even less of an idea what to do about this regret than you would... I can only imagine how awful it must be for you when the agony I already face is going to get even worse when I reach my 30s. My goal is to CTB before that can happen because at this point I know that my regrets are weighing me down and have turned me into a bitter, love-hungry monster who's probably exhausted all its chances.