My dad said he would disown me?

It's unfortunate that your father is still living with such a homophobic mind-set, but it's not uncommon, particularly in older males with limited socio-economic-education status. If I were in your position, I would probably keep my sexuality a secret from my father until I was out of the house and on my own.

speak to a counselor at school

i just wouldnt tell him if you ever became gay

Insecurity and ignorance based in beliefs will often control ones thoughts and lives. There isn't anything you can do about it.

You are 30 years old.  Your father didn't say he would disown you.  He said he would throw YOU out of HIS house.  Any particular reason you whine about him constantly, refer to him repeatedly as an a$$hole, but you never move out on your own?  Eighteenth century thinking?  I think you are confused.  My thoughts?  There is a reason you live with Mommy and Daddy.

Being anti-homosexual is a 19th/20th century trait -- the 18th century considered it normal and not worthy of commenting on (except for a few religious fanatics who equated it with devil worship).

But your father has the right to think what he wants. Just like you do.