idk if its rllly what ur looking for since its not thaattt sad and there is a lot of sex yk BUT https://www.mangago.zone/read-manga/no_better_than_strangers/ i personally think its rlly good, tho i will keep looking for u since i got rid of my list :(
That's alright, thankyou so much (｡･ω･｡)ﾉ♡
https://www.mangago.zone/read-manga/rift_conro/
https://www.mangago.zone/read-manga/kimi_ni_ienai_koto_ga_aru/
https://www.mangago.zone/read-manga/kowagaranai_de_soba_ni_ite/
https://www.mangago.zone/read-manga/kanawanu_koi_no_musubikata/
https://www.mangago.zone/read-manga/replicant_hitsuji_no_dolly_wo_aisuru_to_iu_koto/
https://www.mangago.zone/read-manga/daisy_jealousy/
In the same realm here's a list for mutual pining i.e mutually hidden/unrequited love if ur interested (づ_ど)
https://www.mangago.zone/home/mangalist/1869502/
Tonari no stella
Our relationship is...
Both r straight
Can anyone recommend me really really sad unrequited love manga manhwa which later becomes requited with a good ending `~~~