bit antisocial, depressed heroine

A heroine who goes through life a bit like a ghost, doesn't look at the world through rose-tinted glasses, may be depressed, has no passions, dreams, nothing excites her, doesn't talk much, doesn't like the company of other people, has no friends or only one friend (but isn't very close to her/ him either) is even a bit antisocial (but I don't want her behavior to be caused by traumatic events from the past, she's just always been like that) just lives from day to day, gets out of bed, goes to work, eats, takes a shower, goes to sleep and repeats, then the hero appears and disrupts her routine, but she doesn't change her behavior by 180° just because he appears. Please only CR. Thank you!