Yaoi with an abusive couple ?
Then I would recommend this, it contains incest though.
http://www.mangago.me/read-manga/camellia_minami/
Dispar
Rape, violence, general abuse by seme and others, ongoing
http://www.mangago.me/read-manga/dispar_4u/?vxMD
Cage (Volume 2)
Rape, manipulation, incest, stockholm syndrome.
http://www.mangago.me/read-manga/myuzu_no_gakuen_de_aou/?nsqK
Boys Next Door
Serial Killer, underage prostitute, violence, unreliable narrator.
http://www.mangago.me/read-manga/boys_next_door/
Escape
strong rape warning, unhealthy relationship, open-ended.
http://www.mangago.me/read-manga/escape_kyuugou/
Interview with a Murderer
both abusive, psycho/psychopath, no love, dark.
http://www.mangago.me/read-manga/interview_with_a_murderer/
Ore Dake Mi Nai to xx Shichau zo
yandere, underage, I would rather spend the night in a graveyard than see this yandere a gain.
http://www.mangago.me/read-manga/ore_dake_mi_nai_to_xx_shichau_zo/
Michi To No Souguu
sexual assault/harassment, bullying, not dark
http://www.mangago.me/read-manga/michi_to_no_souguu/
Let Dai
Seme is generally not a good person and does a lot of fucked up shit. Also: this one's heavy.
http://www.mangago.me/read-manga/let_dai/
Bi no Isu
Gonna slap a general abuse TW on this one and call it a day.
http://www.mangago.me/read-manga/bi_no_isu/
Hakoiri Musuko
incest, dubcon, smut, manipulative seme, extremely short.
http://www.mangago.me/read-manga/hakoiri_musuko/
Legs That Won't Walk
Big fat general abuse warning, ongoing.
http://www.mangago.me/read-manga/legs_which_cannot_walk/?Kdzr
Joukakei Kareshi (2nd story)
rape, physical abuse, stockholm syndrome.
http://www.mangago.me/read-manga/joukakei_kareshi/
Kiss Me Princess
The secondary pairing in this is very fucked up. Nicole is also definitely underage and it's implied there was sex. General TW.
http://www.mangago.me/read-manga/kiss_me_princess/
Tips:
ABO (Omegaverse) is abuse central with about 90% of the manga having some form of abuse. I don't read much myself and only keep track of the healthier ones so I haven't included them here. Very easy to find though.
Webtoon-style stuff has brought back some very old tropes as far as couple dynamics go. So that's also a good place to look for psychological abuse/manipulative/domineering semes.
give me one of the saddest stories on here.
http://www.mangago.me/read-manga/the_horizon/
Goodluck, Hun. :')
http://www.mangago.me/read-manga/shii_chan/
You can try Avogado6's stories
http://www.mangago.me/home/mangalist/815165/
These r for me...
strong male lead but no romance and not fantasy pls... doesn’t have to b yaoi
somewhere here
http://www.mangago.me/home/mangalist/626481/
love at fist sight/total infatuation