That guy's comment was really out of line, but, look at it this way, obviously something bout ya made him feel threatened/insecure enough to have to try to degrade you, which, no matter the gender he was born, isn't a very masculine reaction, it's an a--hole reaction but not a masculine reaction. You don't insult other's genders I'm assuming, you don't have to invalidate someone else's gender to feel better about yourself, that jerk does, that difference right there makes you more of a man than he is, least in my opinion.
Either way, school is cruel to begin with, more so if you don't fit into the narrow 'norms', thankfully, school is also temporary, I know that what occurs in school seems like a big deal but in the broad scope of things, it's really nothing compared to the rest of your life, just stay the course, those who don't understand just don't understand, there's nothing one can do to change their minds, but in truth, it's the judgmental ones I feel sorry for, I mean, could ya imagine going through life seeing no farther than the end of your nose like they do? Thankfully the world beyond school is a bit more accepting, you still run across the narrow minded ones but it's not quite as bad because if someone bugs you about it in public, you have every right to tell them to get the hell away from you or face harassment charges, I found myself surprised just how effective that warning can be sometimes.
Just don't let it discourage you, you know who you are, that guy at school doesn't, heck, he likely doesn't even know who he really is to begin with, I tend to study people and have noticed that those who try to be judgmental about others normally live to please the mainstream, and normally, don't even have a good sense of self, you have a better sense of who you are than they do, and that's something to be proud of.
Sadly I don't know much about dealing with the family and improper pronoun thing, so I can't say much on that, but denial seems a likely cause for it, but that's merely an assumption.
