Doom yuri, doom yaoi, doom hetro.

Doomed yuri:
https://www.mangago.me/read-manga/oniisama_e/
https://www.mangago.me/read-manga/huijin_huayuan/
https://www.mangago.me/read-manga/a_story_concerning_sweets/
https://www.mangago.me/read-manga/yume_no_hashibashi/
https://www.mangago.me/read-manga/tower_of_campanella/
https://www.mangago.me/read-manga/brides_of_iberis/
https://www.mangago.me/read-manga/composing_spring_in_this_room_where_cherry_blossoms_bloom/
https://www.mangago.me/read-manga/kimi_to_tsuzuru_utakata/
https://www.mangago.me/read-manga/can_t_forget/
https://www.mangago.me/read-manga/kitanai_kimi_ga_ichiban_kawaii/ (toxic relationship, features some extreme fetishes such as age regression/babyplay, vomit kink, period blood kink, etc.)
https://www.mangago.me/read-manga/this_love_that_won_t_reach/ (age gap, MC is in love with her sister-in-law; rushed and ambiguous ending)
https://www.mangago.me/read-manga/kimi_ga_shinu_made_koi_wo_shitai/ (on-going;doomed side couple and possible doomed main couple)
https://www.mangago.me/read-manga/haru_and_midori/ (MC had doomed one-sided feelings for the second MC's mother)
https://www.mangago.me/read-manga/a_monster_wants_to_eat_me/ (on-going; possible doomed yuri)
https://www.mangago.me/read-manga/the_story_of_a_person_who_grew_a_flower/ (short story; age gap, teacher-student relationship;hanahaki disease)
https://www.mangago.me/read-manga/final_film/ (short story)
https://www.mangago.me/read-manga/avalon_bitter_anthology/ (one-shot anthology)
https://www.mangago.me/read-manga/shiroi_heya_no_futari/ (one-shot)
https://www.mangago.me/read-manga/141108/ (one-shot)
https://www.mangago.me/read-manga/the_story_of_the_princess_and_the_little_mermaid/ (one-shot)
https://www.mangago.me/read-manga/a_bud_in_secret/ (one-shot)
https://www.mangago.me/read-manga/saudade_ni_kuchidzukete/ (one-shot)
https://www.mangago.me/read-manga/efude_to_kurokinu/ (one-shot; toxic relationship, cheating)
https://www.mangago.me/read-manga/you_are_my_soulmate/ (two-part one-shot; omegaverse;ambiguous ending)

Yuris that at first seem like they're doomed, but eventually get a happy ending:
https://www.mangago.me/read-manga/i_love_amy/
https://www.mangago.me/read-manga/getting_to_know_grace/
https://www.mangago.me/read-manga/pulse_ratana_satis/
https://www.mangago.me/read-manga/anemone_is_in_heat/
https://www.mangago.me/read-manga/sugar_girl_drip/ (violence, blood and gore, torture, abuse, child abuse, child neglect, sexual harassment, sexual assault [none of these happen between the MC and FL])

thank you