Differences between a bad person and mental illness (long post but please help...)?

Actually it sounds like she has a personality disorder (please do not think of people like this as Bipolar.... people with Bipolar are NOTHING like this and it just contributes to the stigma we face to have people think this way of us) whether it is considered a mental disorder or just a bad person depends on how you look at it..... personality disorders are considered disorders but they are disorders of the personality (not chemical disturbances like Bipolar) so it is like their personality is twisted... so it IS their personality however twisted. I suggest you pick up a book like "Stop Walking on Eggshells" which is about Borderline PD and how to deal with it.... Your BF will be free in 6 months, until then you need some skills on how to cope with her.