What should I do if I start to doubt my sexual orientation?

First of all, you have to determine whether this is the case, whether you are sexually impulsive to the opposite sex or to the same sex. You can look at those pictures on Woo-hoo-hoo and see if you like them.

Secondly, if you really have a good impression on the same sex, you'd better consult a professional psychologist.

Finally, most of the time you come up with it yourself. You have this trouble, which means you have realized it. It's probably a problem of adolescent thoughts, not really a problem of sexual orientation.

Read more normal books and correct your improper thoughts and behaviors. Good luck.