I was curious as to what kind of Disney fanfic was out there. Not much, and most of what there is is terrible; there's a reason it's a Yuletide-eligible fandom. I did find a truly horrifying Belle/Beast pr0n ficlet that's quite effective.
I think my favorite writing on the subject of depression is by F. Scott Fitzgerald, in the form of his three-part essay, "The Crack-Up." Michel Mok provides a view of Fitzgerald from the outside during this period in his excellent interview, "The Other Side of Paradise, Scott Fitzgerald, 40, Engulfed in Despair." I think Fitzgerald's characterization of himself in tentative recovery as, variously, a broken plate -- a metaphor that's been used by others, but none as well -- and a surly dog has a remarkable truth to it, and a kind of grace in its woundedness that escapes most people who try to write about depression or indeed any profoundly affecting emotion. Its conclusion (barring the, to modern readers, jarring little bit of racism) is one of the most remarkable passages I've ever read, particularly the last two sentences:
I do not any longer like the postman, nor the grocer, nor the editor, nor the cousin’s husband, and he in turn will come to dislike me, so that life will never be very pleasant again, and the sign Cave Canem is hung permanently just above my door. I will try to be a correct animal though, and if you throw me a bone with enough meat on it I may even lick your hand.