The protagonist is deeply anxious about bedbugs and is constantly trying to prevent them from taking up residence in her home. Her internal monologue is focused on scanning for bedbugs a large portion of the time. Towards the end of the book, there as a scene in which she strongly believes she sees bedbugs, but they turn out to be coffee grinds. There's another scene in the climax where there actually are bedbugs.
Spoiler: two people long thought dead have been living in the protagonist's family's house. One of them is constantly watching what the family members are doing. The community members also always know everybody's business.
Spoiler: The protagonist starts to suspect that her home is haunted, but this turns out not to be the case. Instead, two people long thought dead are secretly living in her home and sabotaging things.
There are two shower scenes that I recall. One towards the beginning, where the water keeps mysteriously shutting off, and another towards the end where the protagonist believes she has seen bedbugs and is trying to scrub them off her body. Neither scene is sexual.
The protagonist constantly talks about wanting to get access to marijuana to help her anxiety symptoms. She starts growing marijuana at one point. Other characters also use marijuana. There is discussion of "junkies" squatting in abandoned homes.