BPD: Healing from personality disorder relationships

What do you do when you wake up one morning and actually realize you are in a relationship with a emotionally crazy person? How does it look and feel down deep inside when you know if and when you try to leave your partner, he/she will threaten to call police (falsely accuse you), do harm to themselves and or you, verbally assault, berate you to no end, throw objects, slam doors until the the whole scence resembles and ADULT temper tantrum with adult violent ramifications?