I know that the last thing anyone wants to do when they are depressed is get out and do something and get active. I know. I've been there. And every once in awhile, I pay a short visit there (not on purpose though).
But I can say that exercise really does get your body and brain to produce those natural chemicals that help stabilize your mood and overall, just feel better. The challenge is to just get off the couch and do it once and then commit to it on a regular basis. Overcome the mental part of getting to your first workout and you will be on your way. As I said, I struggled awhile back and just found it very difficult with work, family, life, etc. to find the time to work out. But one day I just got tired of living the way I was that I figured it can't be worse if I get to the gym one day. So I went and now make it a regular habit to go nearly every day. Small steps add up and you will find yourself feeling better. You dont' have to pump iron or run till you throw up. Just get active, bike, hike, exercise, whatever you think you will enjoy. I swear you will feel much better physically and mentally and maybe help you kick this disease to the curb.

My best wishes and prayers for all of you.