>>1412808There aren't that many where the the main mc is a girl and also suffers a lot. I have some suggestions though they're a lot more tame but kinda might be something you want. I do have two manga recommendation that are perfect for what you're looking for but it's pretty dark and not sfw.
these two are very close to what you want but it's manga and not sfw:
>Kimi Ni Aisarete Itakattamc is very mentally unstable and has some horrible "friends" around herself. She has a crush but it makes everything worse for her.
>metamorphosismc decided to become prettier to be noticed and gets a lot of attention from boys. Though she doesn't wield the great responsibility for her new great powers and she just snowballs into a hell she made for herself.
darker anime recommendations though not exactly as what you're looking for:
>Scum's Wishmain boy and girl's love interest is something they're unable to have so they start to date between themselves. Though main girl kinda just bounces around and just hurts herself as she just wonders through life as her real love interest is impossible to be with.
>Made in Abyssthough you said you've seen already check out the movies or season 2 if you've only seen season 1
>Happy Sugar Lifetwo very mentally unstable girls find and loved each other but they're seriously meant to be at a psych ward. Both have had a hard life
Lighter recommendations
>WataMoteGirl who isn't popular and wants to be. Is basically a femcel though she suffers at the hand of herself being an absolute loser.
>The Great Jahy Will Not Be Defeated!living in piss poor conditions while trying to rebuild her demon kingdom
>Kageki Shojo!!a girl school for... dance i think or something. One of the main girls has a dark past with a creep as a child.
>A Silent VoiceMain girl is deaf and was bullied for it
