This types of characters honestly annoy me, I feel annoyed wen characters dismiss other people like their feelings are the only thing that matters, as if the other character doesn't like them, hurting others in the process while making it about themselves, leaving the other characters looking at a wall.
Have seen this recently in a Omegaverse manga where the guy breaks up whit the other because of being unable to give birth while living the guy confused and not knowing wth happened, just for him to go prostitute himself instead.
Niina should legit find someone else, because this type of behavior is toxic.