This could have been written by me - i'm in the exact same position. I had to quit my volunteer job as the people there were real meanies and i thought my time would be better valued elsewhere. You're doing the best you can and that's a good sign that you're determined not to let your problems win. Does your mental health team know of a day centre that you can visit to help structure your days better? The focus would be more supportive than therapeutic i should think. We have that in the UK but i'm not sure where you are so i can only suggest looking for an equivalent. I find trying to be helpful here and being an active part of this community (even if it's only online) makes me feel better. I hope you find something that helps you feel more fulfilled.