I need some sad/unrequited love mangas pls

I’m not sure if this is one of the ones that you’re talking about but it’s called 10 years where I’ve loved you the most and Cocoon of the heart

life senjou no bokura, i haven't read the ones u mentioned tho

Read tags though because a few of these are quite triggering and also I don't know if these fit quite what you wanted but they're all pretty sad
https://www.mangago.zone/read-manga/until_i_meet_my_husband/
https://www.mangago.zone/read-manga/shimanami_tasogare/
https://www.mangago.zone/read-manga/my_broken_mariko/
https://www.mangago.zone/read-manga/claudine/
https://www.mangago.zone/read-manga/what_she_likes_are_homos_and_not_me/
https://www.mangago.zone/read-manga/only_need_to_love_once/
https://www.mangago.zone/read-manga/december_rain/

https://www.mangago.zone/read-manga/j_no_subete/

I have read neither of those but

Forever Honey
https://www.mangago.zone/read-manga/forever_honey/

1866 (BL)
https://www.mangago.zone/read-manga/1866/

Ashita Shinu (Collection of BL)
https://www.mangago.zone/read-manga/ashita_shinu/

Will you marry me again if you are reborn?
https://www.mangago.zone/read-manga/will_you_marry_me_again_if_you_are_reborn/

To Your Eternity (also an anime now)
https://www.mangago.zone/read-manga/to_you_the_immortal/

Tokyo Revengers (Surprisingly, also an anime)
https://www.mangago.zone/read-manga/tokyo_revengers/

Watashitachi no Shiawase na Jikan
https://www.mangago.zone/read-manga/watashitachi_no_shiawase_na_jikan/

One Winter
https://www.mangago.zone/read-manga/one_winter/

If the World Was Ending Tomorrow (BL)
https://www.mangago.zone/read-manga/if_the_world_was_ending_tomorrow/

This Witch of Mine
https://www.mangago.zone/read-manga/this_witch_of_mine/

Kosha Ura no Natsu
https://www.mangago.zone/read-manga/kosha_ura_no_natsu/

Living Will (GL)
https://www.mangago.zone/read-manga/living_will/

I Want to Hold Aono-kun so Badly I Could Die
https://www.mangago.zone/read-manga/i_want_to_hold_aono_kun_so_badly_i_could_die/

Heaven Official’s Blessings (BL, novel/dongua/manhua)
https://www.mangago.zone/read-manga/heaven_official_s_blessing/

I got more but I think this is enough

This one made me cry so hard https://www.mangago.zone/read-manga/paradise_view/