Damn. I must have exceptionally dark taste in media, because I've definitely got a few "well, that was good, but I kinda wish I hadn't read/watched it" things in my history, and
The Road wasn't even close to qualifying. I'd say the film
Threads hit me harder, to pick something with similar setting and circumstances, though that's still not quite in that category.
(It Comes at Night is probably my #1 in that category for film, and I guess Watts' Blindsight in books—both messed me up for days after, the former with some depressive nihilism, the latter with days of fairly intense derealization that weren't too fun—and I'm not normally especially prone to either of those, I don't think)