http://www.mangago.zone/read-manga/straight_kun_to_gesu/
The only one I have read that fits your requirements lmao maybe I should slow it down on the twisted shit.
Anything by Naono Bohra or Sakira. Their mangas have multiple chapters, but each one is a one-shot.
There's also Zariya. She's not psychological nor twisted, but she's VERY angsty. Your safest bet with her is Nemuri Otoko to Koi Otoko, it's not overly angsty and it's HOT.
Most of Yoshihara Yuki sensei works are smut and romance comedy so they’re light reading before bedtime.
These ones contain short stories
http://www.mangago.zone/read-manga/fu_junai/
http://www.mangago.zone/read-manga/secret_x_folder/
http://www.mangago.zone/read-manga/honey_bed_talk/
Hot, non-twisted non-psychological smut one-shots!
I love a good smexy little read before bedtime haha