Is it normal to have feeling that your not straight anymore

I am 17 and I think I'm gay. All of a sudden i just didnt feel straight anymore, like it just didnt feel right. I have had crushes on girls in the past but i never really want to "do" them or really fantasized about them at all. Now I like to stare at pics of shirtless guys, hot guys. there abs, biceps, pecs, and especially v lines are all EXTREMELY attractive to me. When I'm in the locker rooms with the guys at my school I cant help but stare at them to see if they have hot bodies. All the guys at my school are all homophobic and there arent any hot guys at my school that I'm attracted to. I have been having a lot of sexual fantasies with guys in them, i have looked into yaoi in manga, my mom doesnt let me watch porn nor do i want to watch it anyway. Even looking at the yaoi manga is kindof wierd to me. Whenever i see a girls body parts i feel disgusted, i also find looking at guys penises kindof disgusting too although i have one. I just dont find girls body parts attractive although i look at them from time to time. I dont know whats going on with me, im scared because im confused. Serious answers please