am I gay?

Okay guys I need your help I am 19 and a virgin and it's not because I'm saving myself or anything but when I'm in a relationship with a guy I never feel like I want to have sex with them and when it gets to the sexual point I usually back out and end the relationship......so yeah never been in a long term relationship lol..... but when ever I see a really cute girl or a girl has a awesome personality I always think about sex with them and imagine things I never imagined with a guy... I know it sounds creepy.... I'm too scared to try anything even though I want to even just a simple kiss to see if I'm truly gay because my group of friends and basically my whole family besides my mom and aunt are extremely homophobic....help a girl out! What should I do?!?!