What should i do, i don't want to be gay?

i'm 20 years old and i just finished college, the thing is i get really depressed when i think about my future because of myself being gay. i wanna have a wife and children when i get old. I only get aroused with men, i tried to get sexually aroused with women but it just really wont do. Only my mother will accept me when i come out of the closet. My uncle even threatened to kill me if i'm gay. what should i do? I started hating myself because of this. I feel so secluded and alone. Being gay is like a mortal sin here in our country. I get really depressed whenever i see my little sisters because they have a different boyfriend every week and they're very happy with their life..............