Book recommendations for someone who likes bleak, existential sci-fi & horror?

I’ve only recently started reading regularly again, so I don’t have a huge reference pool yet, but these are the books I’ve loved so far: Roadside Picnic Solaris House of Leaves The Road What I liked about them was the bleak/existential atmosphere, psychologically unsettling tone, hostile or unknowable environments, and the feeling of isolation and [...]