Telling parents I'm gay/destroying life. (Help please)?

Ok idk if you have read any of my other stuff but I'm 15. I live in a town of 13,000 in Arizona. My parents are REALLY REALLY reallly super against gay people. My dad doesn't like Ellen DeGeneres, Rosie O'Donnel, Lance B or even my absolutely wonderful business teacher who is a SAINT who is gay. I have had like the "perfect" childhood in that both of my parents were always there except i guess my dad would work alot. The reason I say that is because typically gay teens come from a somewhat troubled background. Well i guess i'm living proof that being gay is genetic not nurtured. But I don't know how to tell my parents. I have to set a lock code on my iPhone and change it every 3 days do they don't snoop on my texts and as for my laptop i have to set like a 32-character code. I don't know what they would do if I told them but i know theyre planning on paying for my college and car insurance which sucks cause I dont want that taken away when I tell them. I mean it NEEDS to happen but I just don't want it to. If i told them maybe some of the tension between my dad and i would actually be released instead of tightened cause I could finally tell him the truth? Idk. HELP PLEASE.