@stranger_in_a_strange_land Are you looking for advice?
I’m worried about your experience with therapists. Have you tried many? Do you have financial concerns with seeing them?
What kind of PhD are you going for? Do you have any interest in your research at all, or was your entire motivation based on doing something for Meg?
Anyway, I think that if you focus on the “so what” portion of your prospectus, it might give you more of a reason to do the work. Helping others is a reason to do your work, although, in my opinion, if your work doesn’t really help others, you should find something else to do. That’s what I’ve always been about. ‘Course when I felt like I’d failed to make any difference whatsoever, it didn’t help much that I had been trying to help. I’d rather be helping than trying.
Do you have a cohort of grad students you can get along with? What about your advisor, or any other professors? I think it’s a little more convenient to find folks to hang with in academia, but still, you have to go after it, which is kind of impossible when you’re depressed.
fluther did wonders for me. I think you are using it that way, too. Hang on. Stick around. You’ll make friends (and you have already), and I’ll bet you’ll find yourself ever so slowly coming back out from under that miasma that depression is.