Can someone recommend me like a gut wrenching sad story Like it can have a happy ending? (...

Ways of parting (I have never cried so much so consistently)
Touch Within the Abyss
The Vessel of a Transparent Love
Hitori To Hitori No 3650nichi

Happy cry
Don't Call Me Daddy

If you decide you can deal with death
Nee Nee, Nene-san
Birthday
Halloween Is Nothing Special
Spring Snow (Odongtong)
A Home Far Away
My Childhood Friend was a God

If you can't find them let me know, I have saved lists on my phone so some titles might not be the ones used on here.

https://www.mangago.me/read-manga/never_understand/
https://www.mangago.me/read-manga/save_me_gently/
https://www.mangago.me/read-manga/my_broken_mariko/
https://www.mangago.me/read-manga/utakata_no_uroko/
https://www.mangago.me/read-manga/magi_no_okurimono/
https://www.mangago.me/read-manga/watashitachi_no_shiawase_na_jikan/
https://www.mangago.me/read-manga/three_days_of_happiness/
https://www.mangago.me/read-manga/ao_no_flag/
https://www.mangago.me/read-manga/haruka_tooki_ie/
https://www.mangago.me/read-manga/the_farthest_friend/
https://www.mangago.me/read-manga/a_girl_by_the_sea/
https://www.mangago.me/read-manga/edogawa_osamu_s_anthology/
https://www.mangago.me/read-manga/mata_onaji_yume_wo_mite_ita/
https://www.mangago.me/read-manga/chi_no_wadachi/
https://www.mangago.me/read-manga/zankyou/
https://www.mangago.me/read-manga/a_lollipop_or_a_bullet/