I've loved Onani Master Kurosawa, Molester Man, Aku no Hana and Oyasumi Punpun so far. I've also read Homunculus, but I didn't enjoy it as much as the other ones.
I love any manga involving the main character growth really. Any recommendations?

Yeah, I love psychological ones too, and yeah, Onani Master and Aku no Hana are pretty good examples.

I'd suggest Annarasumanara, Another, Banggwa hu Jeonjaeng Hwaldong, Hanged Doll, Heptagon, Houkago Hokenshitsu, Melo Holic, Satougashi no Dangan wa Uchinukenai, Shigatsu wa Kimi no Uso, Shion no Ou, Superior Day and The Friendly Winter.

There are a number of Korean webtoons in there, I've found quite a few gems for psychological among them.......not so much for traditional manhwa for whatever reason, but there are some darned good ones from the webtoons.

Good luck finding something to read

Thank you very much! All of them seem interesting, I'll give it a try to all

Good luck

Oh, and I didn't mention it but just in case, those are all off my complete list, so they're out there (at least somewhere ) to read in their entirety.

You could try MPD Psycho, but it's quite the mindfuck. Liar Game also comes to mind.

Monster is the masterpiece of the genre.
Sundome and Ciguatera are similar to the ones you mentioned, but, especially the first one, they have a strong sexual content. If you're okay with it, I recommend them. Also, there is Koi Kaze, but it's about incest.
Gunslinger Girl is my all-time favorite, despite being technically a shounen.
Shi ni Itaru Yamai is a less known title that I also liked.

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What I like in Trivial Pursuit style. Pick your category:

Monster, Liar Game, Sundome and Gunslinger Girl have caught my attention completely.
MPD Psycho looks interesting, I hope it won't fuck my mind as hard as Homunculus did
Thank youu