No, it's only sensible.
Don't come out till you are old enough to move out and support yourself. Then DO it.
You don't have to tell that bunch of willfully ignorant folk a thing. Live your own life and leave them to get on with theirs.
You have been given the wonderful gift of being gay. You'll meet some marvellous people and, if you're honest with yourself, you'll have a happy and fulfilled life.
It is gay people who have kept science, the arts, and so on going. This is OUR civilisation.
First complete your education, then move to somewhere where you don't have to keep hiding your true self - you don't have to screech at everyone that you're gay, but you won't have to lie about it either. Just keep quiet, change the subject, maybe frown a little. Let them live with their problem.