Is this normal for teen depression??

im a 14 year old guy, i have been mildly depressed for a year but it has gotten allot worse in the last month. i just lie on my bed sometimes and dont want to talk to anyone. i am sad all the time and have no interest in stuff that i used to love, im only happy for like really funny stuff and one thing that makes me feel happy is music but my music taste has changed also. i like sadder music like secondhand serenade, and after im done listening to it and i think about the lyrics and thy make me more depressed even more. also in the last week i have started cutting myself. it makes me feel something wich is good for a change. i already have over 40 cuts on me. is this the norm for teen depression or is it different