Niki

I dropped that BL because it was boring ngl, so I'm not sure if these fit/are what you're looking for, but;

This GL is the closest thematically to what you're looking for:
https://www.mangago.zone/read-manga/kill_me_now/

These are GLs with a possessive FL like the ML in Miscreants and Mayhem:
https://www.mangago.zone/read-manga/i_love_amy/
https://www.mangago.zone/read-manga/yandere_meruko_chan_likes_her_senpai/
https://www.mangago.zone/read-manga/hone_no_nazuki_made_aisu/
https://www.mangago.zone/read-manga/your_fetters/
https://www.mangago.zone/read-manga/seasons_in_bloom/
https://www.mangago.zone/read-manga/monomania/
https://www.mangago.zone/read-manga/her_lies/
https://www.mangago.zone/read-manga/saeism/
https://www.mangago.zone/read-manga/after_school_love_affairs/
https://www.mangago.zone/read-manga/indulging_a_crazy_beauty/
https://www.mangago.zone/read-manga/i_m_more_dangerous_than_you/
https://www.mangago.zone/read-manga/manipulate_my_heart/
https://www.mangago.zone/read-manga/adachi_to_shimamura/
https://www.mangago.zone/read-manga/the_barefoot_nina/
https://www.mangago.zone/read-manga/savior/
https://www.mangago.zone/read-manga/useless_princesses/
https://www.mangago.zone/read-manga/tatoe_sekai_ga_owattemo_watashi_wa_kanojo_wo_erabanai/
https://www.mangago.zone/read-manga/is_it_normal_to_raise_a_yandere_heroine_as_a_villainess/
https://www.mangago.zone/read-manga/dang_e_yi_yu_dao_bing_jiao/
https://www.mangago.zone/read-manga/lovedeath/
https://www.mangago.zone/read-manga/non_chan_to_akari/
https://www.mangago.zone/read-manga/mietemasu_yo_aizawa_san/
https://www.mangago.zone/read-manga/saji_chan_no_yami_nikki/
https://www.mangago.zone/read-manga/getting_to_know_grace/
https://www.mangago.zone/read-manga/lonely_wolf_lonely_sheep/
https://www.mangago.zone/read-manga/serenade_keum_kyesoo/ (yandere side character)
https://www.mangago.zone/read-manga/kitanai_kimi_ga_ichiban_kawaii/ (toxic relationship, features extreme fetishes such as age regression/babyplay, vomit kink, period blood kink, etc.)
https://www.mangago.zone/read-manga/the_nest_of_eternity/ (short story;age gap, non-con)
https://www.mangago.zone/read-manga/you_are_my_angela/ (short story)
https://www.mangago.zone/read-manga/ubai_ai/ (short story)
https://www.mangago.zone/read-manga/rapunzel_komoda/ (one-shot)

And here are some mafia/yakuza/criminal organization GLs:
https://www.mangago.zone/read-manga/fall/
https://www.mangago.zone/read-manga/the_song_that_transcends_this_world/
https://www.mangago.zone/read-manga/yakuza_yuri/ (age gap)
https://www.mangago.zone/read-manga/their_phantom/ (violence, kidnapping, confinement, depictions of child abuse and child neglect)
https://www.mangago.zone/read-manga/want_to_sell_me_your_body/ (age gap)
https://www.mangago.zone/read-manga/ada_and_eyva/ (one-shot)
https://www.mangago.zone/read-manga/lit_a_light/ (one-shot)

YOULL LOVE "hwang young's misery" AHHHHHH

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

Forgot to say, theres no rape between the mc and ml but mc has had a couple abusive relationships where SA did happen

https://www.mangago.zone/read-manga/the_world_without_you/
Idk if this one count as grape, but it's good the ML is mentally sick lol

These are all GLs:

https://www.mangago.zone/read-manga/zenbu_kowashite_jigoku_de_aishite/
https://www.mangago.zone/read-manga/this_world_is_mine/
https://www.mangago.zone/read-manga/tatoe_sekai_ga_owattemo_watashi_wa_kanojo_wo_erabanai/
https://www.mangago.zone/read-manga/the_barefoot_nina/
https://www.mangago.zone/read-manga/i_love_amy/
https://www.mangago.zone/read-manga/savior/
https://www.mangago.zone/read-manga/after_school_love_affairs/
https://www.mangago.zone/read-manga/indulging_a_crazy_beauty/
https://www.mangago.zone/read-manga/i_m_more_dangerous_than_you/
https://www.mangago.zone/read-manga/manipulate_my_heart/
https://www.mangago.zone/read-manga/hone_no_nazuki_made_aisu/
https://www.mangago.zone/read-manga/your_fetters/
https://www.mangago.zone/read-manga/seasons_in_bloom/
https://www.mangago.zone/read-manga/monomania/
https://www.mangago.zone/read-manga/her_lies/
https://www.mangago.zone/read-manga/saeism/
https://www.mangago.zone/read-manga/chasing_lilies/
https://www.mangago.zone/read-manga/serenade_keum_kyesoo/ (possessive psycho side character)
https://www.mangago.zone/read-manga/love_thy_neighbor_2/ (cheating)
https://www.mangago.zone/read-manga/my_girlfriend_s_not_here_today/ (cheating)
https://www.mangago.zone/read-manga/kitanai_kimi_ga_ichiban_kawaii/ (features extreme fetishes such as age regression/babyplay, vomit kink, period blood kink, etc.)
https://www.mangago.zone/read-manga/you_are_my_angela/ (short story)
https://www.mangago.zone/read-manga/ubai_ai/ (short story)

Red Mansion

Omg i remember this one!!! This is exactly what i mean when i want a manhwa where they are mentally unstable and insaneヾ(❀╹◡╹)ﾉ~ it made me feel something inside PEAK

ILYY(≧∀≦)

I’LL CHECK IT OUT(づ￣ ³￣)づ