I second the notion of keeping yourself occupied. Depression works with your mind to create a vicious cycle. The worst thing you can do is wallow in it and let it take over you.
I've been in and out of depression for a while, too. About the only thing that helps me is being productive or kickin it with a single chick. Often times, I'll read something new, teach myself something. Try to learn a new language. I'm currently working on French. I'll try to work on some beats or write some new songs. Maybe draw, study for school. Exercise helps, too.
I know how you feel. Depression sucks dick. Good luck. You'll be okay.
this great blue world of ours seems a house of leaves, moments before the wind