That's a tough situation. I guess I would just advise trying to find other groups who will accept you for who you are. You're not alone, but you might have to work much harder to seek out people who are able to understand what you're going through.

Lemmy is a good substitute sometimes but you really need IRL support as well.

If you can afford to, move somewhere more tolerant

One thing to take a moment on is double checking if you really are being isolated or if you're just perceiving what you expect to see. The one person I've known closely who has some gender uncertainty/questions had some pre-determined expectations of what would happen, and as a result saw them validated at every turn regardless of the intent.

It's possible that what you see is truly non-acceptance, but take a step back to be sure it's not just a bit colored by your own expectations of others response.

what about the cases where these reasons effectively trump any potential loneliness their actions would cause?

The mere act of understanding the reasons that make loneliness worth a course of action precludes rejecting societal norms out of hand or following them uncritically. So, I think you're good.

I don’t really have any advice for your question, but I want to applaud you for having the kind of strength needed to be who you are.

Perhaps, not the most pleasant thought, they were never really your friends if they cannot accept who you are inside—which has no impact on them or anyone else but you.