P.S. Regarding feeling asexual and sometimes aroused by things that trouble you, I hope you will not worry about this, but accept yourself, be very gentle and caring toward yourself. As you get older, you'll learn that no fantasies are inherently harmful. It is ok to be turned on by anything, as long as you are not acting out fantasies in real life that hurt you or someone else. As you give yourself permission to have your thoughts (gently and over time) you will find it gets easier to change the things that turn you on to things you enjoy more.

There are people out there to help you work through these things. It can be hard to find them at 15, and hard to wait, but it does get much much better.