I see you're asking for novels, but what are your feelings on reading poetry for this purpose?
I ask, because I once had a period of about 2 years when I had a lot of problems sleeping due to anxiety and racing thoughts that wouldn't shut up, and I found reading (and especially memorizing) poetry was an effective way of quieting my brain. It was stimulating enough to give my attention something to latch onto besides the nonsense screaming in my head, but not so stimulating that I'd become engrossed in a poem and have to stay up all night finishing it. In fact, the more dry and boring the poem was, the better (Alexander Pope, I salute you).
Just to clarify -- I do read poetry and enjoy it, but when I was reading it at night to quiet my brain, it wasn't for the enjoyment of the content of the poems, but for the (uh) literal act of reading it. The language of poetry (esp that written before the 20th century) is unusual and challenging to parse, so it takes some concentration to read, which siphons away mental resources away from those obsessive thoughts. That's also where memorization is useful -- it takes even more concentration to memorize, and in return, you build up a stockpile of poems you can mentally recite at any time you want to derail a thought spiral.
And of course, so many of those poems are really beautiful, and powerful, and voice sentiments that affirm life and one's place in it.
Anyway, if this sounds appealing to you, I recommend any big honking anthology of poems, like the Norton Anthology, which is (*checks listing*) a whopping 2,182 pages long and 6 inches thick and could provide years of refuge from The Night Terrors.
To follow your nose and to be prepared to read anything is good advice. Something really crazy like the Norton Anthology of Poetry (huge book, biblical proportions, designed for undergraduates) is the kind of deep pool that you can dive into more or less at random. Enjoy your reading!
mhmm. u cn buy a copy of this for $26 USD, it's got all kinds of poems in there. otherwise just torrent a copy and read through it, real easy. gl