I'm confuesd about my feelings towards my friend?

Well me and my friend Hannah are very close, and we both believe that teens should not date intel they are 17 (we are 15) but for an while now, I've had an crush on her. And I think that she has an crush on me to, cause we have giving each other nicknames, I call her chibi and she calls me her J-master, and when we are alone together, we always flirt. And when we sit next to each other, we always end up holding hands. Even though I want to be with her, I always end up lusting after other girls, so that is just my teenage hormounes right? and just a few days ago, we were at her sisters grade 9 grad, and Hannah and I sat next to each other, and flirted a little bit, but when Hannah started talking to an other boy, a boy who is one of her friends who she hasn't seen in awhile, and while they were talking, the boy was blushing, and Hannah was talking weird, but then after that they never talked again and Hannah stayed near me, and when they were talking, I fellt really jealous. So I'm asking, is my crush on Hannah is real or just teenage hormounes, and do anyone thinks that she likes me also?