Who am I?

I am the girl who smiles in the halls I am the girl who says hello. I am the girl who loves to help, And I am a girl that you know. Yet, I am the girl who cries each night I am the girl who hates her home. I am the girl that used to cut, And I'm a girl no one knows. You are a person, you are my friend. Or at least, that's what you say. And yet you don't see through the mask That I wear every day. I smile at you, and everyone else, And nobody seems to see All of the depression and all of the pain That is bottled up in me. Do they now know, or do they not care? That I suffer day and night. Smiling in the sun, crying in the moon I'm almost out of fight. Each night I want one thing, To freeze and watch time pass me by. So let me ask you a simple question, Who am I?