https://www.mangago.me/read-manga/if_you_wish_for_my_despair/ (ths one is so gutwretching for me and my go to when I wanna cry and feel pain)
https://www.mangago.me/read-manga/my_beloved_oppressor/
https://www.mangago.me/read-manga/bones_and_petals_drac/
https://www.mangago.me/read-manga/exotic_love/
https://www.mangago.me/read-manga/into_the_blue_water/
https://www.mangago.me/read-manga/ways_of_parting/
Maybe this?
https://www.mangago.me/read-manga/the_walking_cat_a_cats_eye_view_of_the_zombie_apocalypse/
And I’m a sucker for animals, so their sad stories will definitely make me cry, but it’s not all sadness, so not sure it’ll fit your profile:
https://www.mangago.me/read-manga/hello_veterinarian/

Can someone recommend me a good angst? I don't mind if it's bl or not, just badly want to read something sad:[