Psychological/horror BL

Try Interview with a Murderer and Black Mirror

Also Hotel Phryne and Nevermore

Try the beast must die

You can try this tag search, or use your own tag https://www.mangago.zone/tag/horror%20BL/

This manhua https://www.mangago.zone/read-manga/copper_coins/
is adapted from an incredibly well written novel of the same name https://www.novelupdates.com/series/copper-coins/
It's a very moving story! That author is perfection!

https://www.mangago.zone/read-manga/save_me/

https://www.mangago.zone/read-manga/lifeless_man/

https://www.mangago.zone/read-manga/criminal_interview/

https://www.mangago.zone/read-manga/hidamari_ga_kikoeru/