Wow, dude ! I admire you for being able to stay calm, facing such a hurting gender policy !
Jigsaw is right, if everybody aware that sex is not the same thing as gender pay attention to educate people around them, world can sloooooowly become a bit more comfortable for trans* people.
Anyway, it's always difficult to stand for yourself, even if you are out (and especially if you are new at being out and not out to everyone). I mean, just this evening I said I-don't-remember-what to my brother (to whom I said I'm agender) using a masculine form of an adjective (in french we make adjectives agree with the subject) and he corrected me. I said "we don't care". Like to say "remember, I'm not okay with gendered things" and he said "yes, we do care". And I gave up. I wish I had the courage to say "it hurts me when you correct me when I use a gender or another. please let me use masculine when I feel like it's appropriate". But I couldn't. It's a long road...