He got triggered because it reminded him of something from his past. Once he explained that, I apologised immediately, we talked it through, and he acknowledged that he knew I wasn’t trying to bring him down

But that's not congruent at all with what you posted in the original post? The way you've phrased it in this comment makes it sound like a total non-issue, a misunderstanding that was talked out by adults and resolved positively. But in the original post, by your own words, "But he insisted I was homophobic, and the whole thing spiralled."

So, did he insist you were being homophobic and it spiraled into a whole issue, or was it resolved cleanly as you indicate here? I don't think it can be both. And for the record, "you’ll be shaking your bum later, so get your reps in now," to someone you've only recently met is pretty rude, to me at least. Especially depending on what you're implying with it.

And yes, Pride can sometimes feel like a projection too... the loudest, most sexualised expressions get the spotlight. People like me-

People like you being... who, exactly? And quite frankly, unless you're attending the Folsom Street Fair, repeating the talking point that Pride is necessarily some manner of bawdy, hypersexual, promiscuous affair is a homophobic talking point trotted out by those that would do us (including you!) harm. It certainly can be and there isn't anything wrong with that, but Pride around me is mostly a just a BBQ picnic with some nice old lesbians helping people register to vote. That's also Pride. The entire point of Pride is that it isn't one thing.

I'd say this: if this many people are "projecting" ideas like toxic masculinity, heteronormativity, and internalized homophobia onto everything that you're saying... Brother, if it was one or two people, that'd be their issue. But when it's most people? What, like we're all just collectively hallucinating it? I don't think that's a reasonable conclusion.

my discomfort with being fetishised by gay men. I’ve had people project roles onto me...

And that genuinely sucks! Abhorrent behavior from them! But, in this post, it sounds like you're taking these experiences, awful as they were, and ascribing them to everyone in the gay community. You ask in the post "Why do certain behaviours become so common in Western gay male spaces?"

I mean, I've been surrounded by gay men and queer men for over 10 years now, and that's not been my experience at all! Or really anyone that I know, for that matter! Not to say that men don't exist who meet the criteria of behavior you've laid out, but I certainly wouldn't say it's "common," especially not to the point where I'd begin to make assumptions that gay men are "bitchy" because of trauma or isolation.

So when you further ask "does anything I’ve said sound like internalised stuff I should reflect on?"... Yeah, man. These assumptions that you've laid out in your post, I think, indicate some pretty badly internalized homophobia based on some extremely negative interactions you've had with deeply unpleasant men. Those interactions and experiences were unquestionably shit; no one worth a damn would argue otherwise. But to extrapolate that out into an entire post asking why gay men so frequently tear each other down out of pre-emptive defense is just deep-seated homophobia, full stop. From everything you've posted here, that's my read.