My mother was the same way. I never knew which mother I was coming home to every afternoon after school---the sweet one who greeted me pleasantly at the door and took me to the beach, the weepy hot mess who blamed me for all her problems, the drunk one who blamed me for her drinking, or the angry, hostile one who screamed at me for hours and punished me for any real or imagined offense. She made me feel horrible about myself. I don't know if she was bipolar or not, but she sure displayed a lot of the symptoms.