There is nothing wrong with you, don't ever let anyone convince you to think otherwise, including yourself. There is nothing wrong with liking older boys, my aunt and uncle are 15 years apart and they're one of the happiest married couple I know.
Of course, being a minor adds a bit of a problem, both legally and ethically for some people.
As long as your happy and safe, being cautious and don't let anyone pressure you into doing something you don't want, not having your full consent.
Don't fret to much about it, you are still young, and there'll be ton's of boys catching your eye, just sit back and enjoy the ride. Don't take things to seriously.