Kaater, I don't really have any suggestions but just wanted to say I'm so sorry you struggle with constant pain. As someone who suffers from migraines and fibromyalgia, although not as severe as what you're going through, I understand how physical pain and the effect it has on one's ability to be active can lead to depression.

I once had a migraine for 3 weeks straight and was largely incapacitated. It was horrible, so I can't imagine what you're going through. Hang in there.