Not a doctor but I've been reading a lot lately on this. Sounds to me like you have a very low serotonin level (perhaps none?) an immediate and temporary fix would be foods high in this, say like Bananas! Sounds like you're eating a lot of fruit already and you did say that you get some relief from exercising so your adrenelin must be way way down - there's a new 'natural' drug on the market - you could ask your doctor for a serotonin supplement - it exists and I'm sure he could order it for you - it's NOT an antidepressant in the traditional sense of the word - anyway, look into raising your levels of seratonin/adrenalin and I reckon you're Depression will show a marked reduction - good luck!