I can relate to a lot of what you said as a gender non-conforming woman. I thought I was gay for the longest time and tried hiding it---also thought I needed to transition to be "normal" and "straight".

I hope you don't mind me asking, because it's a rather personal question(you don't have to answer if you're not comfortable--), but why do you feel as "perpetually single"? Was it in relation to biphobia or other things? I felt that way before too...For me, just that the women I liked were straight or I was too scared to ask or the men that I liked rejected me for being too "boyish" or they ended up being creepy and only liking me because I was "exotic".

I wish more bi men would come out, but I get why they don't.

I can't speak for bi men, but from what I've seen, they've been told they're secretly gay, that they don't exist, have HIV/STD, are not masculine enough, etc and I think it may be so constant that they just get tired of trying/bothering to be visible. I have an article posted on this sub and there's this quote:

Suresha pointed me to a 2005 New York Times article with the headline “Straight, Gay, Or Lying? Bisexuality Revisited,” the fallout of which he saw as “a disaster for bi people.” The article reported on a new study “cast[ing] doubt on whether true bisexuality exists, at least in men.” The study in question measured the genital arousal of a small sample of men and found, as the Times summarized, that “three-quarters of the [bisexual male] group had arousal patterns identical to those of gay men; the rest were indistinguishable from heterosexuals.”

I feel you though, I would love to hear more from bisexual men to see what they go through. Your question would be a good post here and over at s/LGBDropTheT since it has a wider audience.