I was just like you when I was in high school, I thought that most of the guys were immature or jerks. I was considered an outcast with very few friends, it didn't help that I was painfully shy.
May I suggest something? Is there anyone younger than you at your school? I was 17 and I started liking this one boy, and he was 15. He was actually more mature than the guys older than me. I know it seems crazy, but just try it. Another thing,if you know a guy that seems like a jerk when he's with his buddies, try to talk to him alone, he might amaze you. I knew one jock, a basketball player, he was the BIGGEST jerk at my school- then I talked to him alone. He was actually really nice and very friendly.
I don't know if any of this will help you, but best of luck. ~Lyn