I can't imagine how it must feel like to have your parents dislike a part of you that is as much you as the head that's attached to your body...
But, perhaps your mother just doesn't understand what "gay" really means.
What you have to understand is that your mom is quite a bit older than you, and she likely has lived trough the time where being a homosexual wasn't accepted, and might have hear lots of bad, prejudgefull, things about them.
Your mother might think that being gay means that you like to wear provocative leather outfits to strange bars, and treat STD's like collectibles, while this, hopefully, isn't actually the case.
Have you ever tried talking talking to your mother about what it's like to be a homosexual?
Maybe she just doesn't understand, and if you explain her that being a homosexual only means that you're attracted to men instead of woman, just like your mother is (presumably) only attracted to men, and not to women, she may get a little bit more understanding for you.
And, if you don't know what to say, I'm shure that there's hundreds of websites and orga's out there that will give you advice about talking to your parents about being LGTB!
It's as simple as a misunderstanding. You don't want to hate your mother, and your mother doesn't want to hate her child. So, if you haven't, I'd really suggest talking to your ma! c: