i'm not sure anymore...?!

first of all; if your one of my friends at school and you know it, please stop reading this.... its personal..
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I'm generally a very happy person, i have a lot of friends, i get straight A's, and around everyone everything is optimistic and I make the best things out of everything. If people yell at me or say I'm crazy I just smile and shake my head and not listen, I have the BEST parents in the world that support me for who I am... but I don't know who I am anymore... I recently turned 13 and love music (it's my life) and I'm starting to really like rock-ish bands like paramore, evanescence, slipknot, ect. I look at myself in the mirror and I feel like I am not going down the right path, but everything is so perfect right now and I don't want to mess anything up.
I'm just that happy girl at school that's breaking apart inside, but unsure what the cure for it is because I don't know whats wrong....
Basically, what should I do... I don't really know anymore...