You know what? I'm not either a doctor nor a psychiatrist, but what you've described sounds like chronic fatigue syndrome, not depression. Or (second vote) hypothyroidism, which also can create some of the symptom set you describe.

Both depression and CFS have no known causes, which makes their diagnosis problematic and their treatment even more problematic. But overall I would suggest that you look at CFS -- IMHO it seems to be a better fit to your symptoms.

Again, I am not a doctor and this is just an off-the-cuff opinion.