What Do You Do When Horror and Dread are Appropriate Responses?

I spent much of the last two weeks in a state of dangerous anxiety. Partly this was due to overwork: I took too long researching a forthcoming essay and not long enough writing it, and had to pull a fourteen-hour writing session (broken only by walks, so that it actually ate up the entire day) last Friday. I think the piece will be pretty good when it e…