https://www.mangago.me/read-manga/unintentional_love_story/
https://www.mangago.me/read-manga/a_b/
https://www.mangago.me/read-manga/neko_x_neko/
And if u like bl with babies then...
https://www.mangago.me/read-manga/shima_chanchi_no_tsugaijijou/
And some non-bl shorts...
https://www.mangago.me/read-manga/kimi_ga_futte_kita_hi/
https://www.mangago.me/read-manga/please_call_me_red_panda/
https://www.mangago.me/read-manga/the_ghost_that_lives_in_the_doll/
Similar to An Uncomfortable Truth:
- http://www.mangago.me/read-manga/save_me/
- http://www.mangago.me/read-manga/bastard_hwang_youngchan/
- http://www.mangago.me/read-manga/hwaja/
- http://www.mangago.me/read-manga/metronome/
- https://www.mangago.me/read-manga/psycho_young_dream/
- http://www.mangago.me/read-manga/hanged_doll/ (this is rather creepy than dark)
- http://www.mangago.me/read-manga/subtle_disaster/ (read on line webtoons)
- http://www.mangago.me/read-manga/my_student_can_t_be_a_psychopath/
And then here's some cute and funny stuff to read after lol
- http://www.mangago.me/home/mangalist/662140/
- http://www.mangago.me/home/mangalist/717570/
I'll just assume you're asking for stories with mxm relationship based on your manga lists. I haven't read An Uncomfortable Truth, but if you're looking for messed up manga, I suggest Feeding Lamb, any of Harada's works, and Warehouse.
After that, you can read Megumi and Tsugumi, Simplified Pervert Romance, Meet me After School as chasers. The translation for the last is bad af but the story made me laugh from the beginning to the end.
I want some fucked up stuff like "An uncomfortable truth".
And some cute stuff to cure my depression after that.