Kisa,
Couldn't tell from your post, but have you seen a doctor? Sometimes medications can be a big help. As soneone who has suffered from depression for years and only in the past few done something medically about it, I can say don't wait.
Physical activity is very important as it releases chemicals into your body that naturally fight depression. That's one vicious cycle: When you're depressed you don't feel like doing anything which makes you more depressed. Get on your feet and break it.
Your diet can also affect you greatly. Carbs (don't over do them) do help you with feeling positive. When I'm depressed I step up complex carbs like whole grain foods. Just make sure your diet is balanced. And don't overdo caffiene or stimulants.
If I understand your myspace, you write songs. I do this too and it helps, so keep it up.
Prayer is quite important too for me. Sometimes I set a chair beside the bed and visualize God sitting there as a friend. Maybe it sounds hoaky, but for me it helps me to have a running conversation, which is what prayer is all about, rather than anything complicated. Talk, then stop to listen. Repeat.
Last, if you don't volunteer with a local charity, do so. There are ALWAYS people who are worse off than you. And somehow helping other people is like a good kick where we need it. It helps us put things in perspective.
And if you need to talk drop me a message.
Peace,

Kristi