My recommendations would be:
https://www.mangago.zone/read-manga/leo/
https://www.mangago.zone/read-manga/our_not_so_lonely_planet_travel_guide/
https://www.mangago.zone/read-manga/koimonogatari/
https://www.mangago.zone/read-manga/10_dance/
https://www.mangago.zone/read-manga/incidentally_dyed_by_spring_s_love/
https://www.mangago.zone/read-manga/the_man_who_can_t_taste/
They're all on-going except the last two.
The authors didn't go full psychological mode, these titles might not be exactly what you're looking for, but reading them you completely understand the characters' struggles and they're all humanly flawed, scared, messy. You understand their choices and thought process, even if you don't agree sometimes.
Thank youu (●'◡'●)ﾉ
Could someone recommend me BLs where the author explores the character’s psychology in depth? Where the characters really feel human