Two things, and pretty much only two things:
1) Imagining scenes for my books (https://keripeardon.wordpress.com/);
2) A guilty conscience.
Unfortunately, I think the two things are linked. The ability to imagine people and places and dialog that doesn’t exist also allows me to imagine horrible outcomes for whatever I feel I’ve done wrong. And I tend to make mountains out of molehills when it comes to feeling guilty. Late library books are a terrible burden. I just hope I can sleep tonight; I noticed today that my bank account was in the negative. I fixed it as soon as I saw it, but that could easily make me feel guilty for a week–minimum.