Hm, it's a very particular mood that I can't quite describe. Oddly, when I'm stressed, I sometimes gravitate towards books that I know will be troubling to read. Probably some sort of cathartic instinct. For a while I put M.R. Carey in this category (see Fellside) but he tends towards a twist of surprising hope at the end, even if half the cast is horribly dead. And I like that in his work, but it's a different thing.