Thinking of you, shaggy dog. I have also found it to be incredibly frustrating when I'm doing everything I'm supposed to do (going to therapy, taking meds, exercising, spending time with friends, etc...) and still feel like crap. One thing that gets me through it is that I've had the experience of depression enough times to know that eventually it will lift a little, and that I've managed to get through it before. It sounds like you've had multiple episodes of depression as well? What has helped you to survive until the clouds lifted in the past? For me, at my worst moments, what has helped is figuring out how to get through a few minutes at a time, using distraction, calling my therapist and my friends, and trying to get outside when I can.
Take care. You are in my thoughts.
garden gal