My father doesn't want a relationship because I'm gay? (HELP)

My older brother passed away very suddenly in June, just two days after coming to my graduation. At this point I had already come out to my family but they refused to acknowledge it. After the funeral I figured my happiness didn't matter and that I should just play it straight.
But it made me feel sick. Everyone around me was trying to push me into dating men, even my roommates. One night, out of frustration, I downloaded an app marketed to queer women just to see if there were any other gay women in my area. I live in a very backwoods area. Shortly thereafter, my girlfriend reached out to me; we chatted for about two weeks, and both felt a connection, before deciding to meet up.
Our first date--Sept. 7--was the best day of my life. I felt alive for the first time since he passed away. We snuck around for awhile, not out of spite but out of fear, until one of my roommates outed me to my family without my knowledge.
My father was understandably very angry. He called me a liar and a scumbag and said that he didn't consider me family. I did my best before going home for break to mend things. It wasn't enough for my family. As a Christmas gift, my girlfriend gave me a necklace with my brother's football numbers engraved on the back; it was very sweet and thoughtful. I assumed that because I told my mom who it was from that she would tell my dad. She didn't, and he was angry that he wasn't told.
This was part of a larger conversation in which he and my mother both said that they think we're only together for sex, that I sought out a relationship, and that they feel obligated to contribute to me. My father went so far as to say he doesn't love me anymore.
Since coming back from break I have done my best to meet their demands: pulling my grades up, keeping in touch regularly, doing my best not to mention her too much. Not being able to be myself fully with them makes talking to my father very strained, to the point where a simple and vapid phone conversation makes me cry uncontrollably--without him realizing, of course.
My girlfriend gave me a beautiful promise ring. We just celebrated six months together and can't wait to spend our lives together. I am happier than I have ever been in my life, even though my entire family is against us. But I love them. I love my father very much; he doesn't seem interested in having a relationship.
What should I do?:help:

 

father76, I am sorry to hear about your situation, but thank you for your kind words. I really hope that your point about fathers loving their children is true:'(
Euler, I can't cut them loose. They're paying my tuition; they've paid for everything I need because of my cerebral palsy. More importantly though THEY ARE MY FAMILY. He is my father. Cutting them loose, especially after everything we've been through, is cruel. I don't have the heart or the conscience to do so.
What tears me up most is that they accept my dead brother more than they accept me. He made the worst mistake a person can and it cost him his life, but instead of being angry they honor him. They should be angry. They should be hurt. My girlfriend has done NOTHING wrong and yet they treat her like she is some predator. In reality, if it wasn't for her I would have ended myself in despair. The only reason I keep going is so that we can have a future together; my brother would love her. He would want me to be happy. THAT'S how I'm honoring him. He never would've turned his back on me.
And that's what breaks my heart the most about this whole thing. I don't have anybody in my family who will stand by me:'(