For me it’s oyasumi punpun, one fucked up manga that is
http://www.mangago.zone/read-manga/the_prisoner_in_the_miniature_garden/
It was a bit sick but it was also really sad. Honestly, I don't know how to feel about the manga but I just can't bring myself to read it again.
*How to get depression*
-zankoku na kami ga shihai suru ( http://www.mangago.zone/read-manga/zankoku_na_kami_ga_shihai_suru/ )
-dark heaven ( http://www.mangago.zone/read-manga/dark_heaven/ )
-let dai (but i've read it 3 times already so i promised myself i wont read it again cause every time i read it i start crying on a certain event) ( http://www.mangago.zone/read-manga/let_dai/ )
-oyasumi punpun ( http://www.mangago.zone/read-manga/oyasumi_punpun/ )
-5 centimeters per second( http://www.mangago.zone/read-manga/5_centimeters_per_second/ )
-the devil's trill ( http://www.mangago.zone/read-manga/the_devil_s_trill/ )
- nana ( http://www.mangago.zone/read-manga/nana/ ) (but im still rewatching the anime :'()
http://www.mangago.zone/read-manga/michiru_heya/ it affected me so deeply with its stupidity im never reading it again.
lol sorry if i offended anyone, i saw that it was among popular ones, but i really really dislike this one xD
http://www.mangago.zone/read-manga/diamond_dust/
It was hard for me to make it through to the end of this. I was finishing it at about 3 or 4 in the morning and I had to go finish reading it in the bathroom, so I could cry and blow my nose without waking anyone up. Lol.
#2) http://www.mangago.zone/read-manga/nigatsu_no_eden/,same dude, same
i had no other words.
http://www.mangago.zone/read-manga/oni_wa_warau_ka/
What Manga/Manhwa/Manhua affected you so deeply you can't read it again? I'll start - for me only two come right to mind -
#1) Hydra
#2) CANT FIND TITLE - young artist finds tattooed guy in snow then draws him - looked and looked for title can't find had 'orchid' in title I thought ... doesn't matter can't read again shredded me.