I've read a few dark psych manga this year and am looking for anything like Aku no Hana, Goodnight Pun Pun or Boy's Abyss please.

I'd say The Bloody Mountain Path or the one with the office dad with a bratty teen daughter but those dragged on forever.

Please and thank you!

Edit: I've read Gakkou Gurashi/School Live as well.

Homunculus
NHK not dark but hits on a similar level

Do you recommend the manga or the anime of Welcome to the NHK?

I'll check out Homunculus!

NHK anime was a bit different to the manga. I would suggest manga but anime isn't bad either.
I'll also suggest Monster. While it's mostly thriller/mystery, psychological and dark aspects are still there.

Bastard (HWANG Youngchan)
Boku Dake ga Inai Machi Anime might be better.
Bokura no Hentai lgbtq
Shiki Also has an anime which is pretty great. Could have a slow start.
Mirai Nikki I recommend the manga over the anime here.
Boku wa Mari no Naka By the same author who did Aku no Hana.

Only look at these recommendations if you're an adult:
J no Subete Also would put it in lgbtq but this one is 'heavier' and deals with a lot of rough stuff.
Killing Stalking Contrary to popular belief, I wouldn't say this is a BL or even a romance. It deals with two criminally insane people and their obsession with each other. It is R-18- heavily sexual and violent.

The Black June
BASKI
Ripple Rooter

Quote from kkyuuu

The Black June
BASKI
Ripple Rooter

Hate the fact that those comics are behind a paywall but Baski really got my attention.

i haven't seen the three mangas you've mentioned yet but i think "Chi no Wadachi" by Oshimi Shuuzou falls into that category and is worth trying.

Chi no Wadachi

also these mangas:
I Wanted to be Hurt by Love
Saiteihen no Otoko (weird shit)
Life
Umibe no Onnanoko

Kasane by daruma matsuura edited: https://www.mangaupdates.com/series.html?id=34971

⊂(・﹏・⊂)

Quote from fieyaaah

i haven't seen the three mangas you've mentioned yet but i think "Chi no Wadachi" by Oshimi Shuuzou falls into that category and is worth trying.

Chi no Wadachi

also these mangas:
I Wanted to be Hurt by Love
Saiteihen no Otoko (weird shit)
Life
Umibe no Onnanoko

Kasane by darum ...

Ah so its called Chi no Wadachi. I actually described that one in the OP but it drags on. I've read it up to the final arc but the pacing is just taking forever for it to just end already.

I'll check out the rest of what you posted, thank you for the reccs!

Edit: Also reading but am waiting to binge Kasane since I really like that one!