Well, get out, do something. Nobody keeps you from spicing up your life.
I wasn't saying that you should get out and be social with people. There are -lots- of activities that don't really involve interactions with others. But the point is, you can't fight depression by being inactive. The only way is to get out and distract your mind. The reason why you are depressed is that you are sitting at home, feeling useless.
You are 17 and pretty hot. And as a human being, you have virtually all capabilities everyone else has, too. For God's sake, you can't waste your life like that. Nor can anyone else.
Honestly, doing exactly that plain blunt thing has essentially cured me from anxiety, depression and a feeling of uselessness. I went out, saw life, and enjoy most of it now. Of course, it's not always peachy, but nobody said it would ever be. However, I know that "just doing it" is eventually the only proper course of action. At some point, you just have to do something.
People here are partly too negative, or too commiserative. The latter only reinforces your thoughts that it's ok to live the way you do, because others do, too. And it's not ok, because that's just plain wrong. I find "caring" at this point more detrimental than telling the blunt truth.