How to know what i am..?

ok so i'm a girl who's 15..and i'v been dating this girl 4 bout 4 months now and at 1st i said i was bi to parents they hated it cuz its a sin rite? so as 2 months gone by i started getting strong ually feeling for her. and i started getting turned on alot by her and **** like that..but i didnt understand what i am cuz i told my parents i was bi they hated it and i'm starting to think i'm a lez cus i was on youtube cuz i do online schooling .. and i had to learn about ually stuff and they were showing a guys d*ck and when i saw that i got turned off so bad i threw up..and i told my grandmom and she told my mom and my mom didnt say anything then my grandmom said "oh you should be looking at how she reacted to see that" and now i know that bi means you like both sides and **** but if i didnt like seeing that then thats means im les rite? oh god my family gunna hate me i mean the reason i said that was becuz the other nite my mom and dad were talking bout me and my gf and like my mom said i want grandkids *but since i'm with a girl it cant happen* and so she said oh well looks like my other daughter gunna have them*and like i cryed cuz my own parent dont like who i am:'(* and 4 there info sincents are finding ways for girls to have and they can have kids now with my gf i do see her with me forever we plan on getting married and **** like that and dying together but if i'm not turned on by a guy's d*ck then dose it mean that i'm les?? idk pls help me i'm very confused:(..