Coming out help?

Okay well i am 15 and i have felt attracted to girls for as long as i can remember. My friends always point out guys they think are cute and i play along because they dont know. But it is also wierd because i dont feel an attraction to girls my age (i think its because i consider them all immature lol and thats a pet peeve of mine) but i feel attracted to a lot of adult female celebrities. I want someone to know so i can get to know someone and like them because everyone else is dating and im not because i dont feel anything towards the guys i date and im not out yet but im scared to come out for the fear that things will change for the worst. My parents wouldnt mention it but my siblings would joke and tease about it which i could handle. The main problem is that i live in a very southern state and i dont want homophobics at my school to bully me or say anything to me. What should i do?