Idk if you’ve read this but it’s not exactly ptsd and I’m not elaborating more just know that I’ve put you on to something peak. Also pls don’t let my arrogant (but right because I know this peak) attitude put you off on reading this.
https://www.mangago.zone/read-manga/guardians_of_the_lamb/
I''m pretty sure there were a lot more but these are the main ones I remember (the most severe cases, mostly SA):
https://www.mangago.zone/read-manga/like_a_wind_on_a_dry_branch/ (sexual abuse and other stuff, she has it rough)
https://www.mangago.zone/read-manga/yeonwoo_s_innocence/ (bullying, sexual abuse)
https://www.mangago.zone/read-manga/one_husband_is_enough/ (I think it's ptsd? well she gets traumatized after being sa'ed by basically every man/woman she meets)
https://www.mangago.zone/read-manga/taram_taram_taram/ (survivor's guilt, sexual abuse)
https://www.mangago.zone/read-manga/screw_the_noble_life_i_m_going_home/ (physical child abuse)
https://www.mangago.zone/read-manga/moral_less_scandal/ (death of family, husband's betrayal and later SA... and well, her own suicide I guess)
https://www.mangago.zone/read-manga/setsuna_graffiti/ (death of family)
https://www.mangago.zone/read-manga/my_school_life_pretending_to_be_a_worthless_person/ (physical child abuse)
https://www.mangago.zone/read-manga/sensitive_boy/ (sexual abuse)

Any straight stories where the fl or the ml has ptsd?