Looking for disturbing fiction that will further weigh down my psyche.

I need something disturbing to read that will haunt me for the rest of my life and will make me lose sleep. Ideally, similar vibes to A God In The Shed by JF Dubeau, Last Days by Brian Evenson, The Cipher by Kathe Koja, but less viscerally disgusting than Albert Fish In His Own Words by John Borowski (the one book that made me feel so sick I didn’t finish it). Fuck me up. Thanks.