It must be very frustrating for you. Sorry, this frog of little brain has no answers.
Having your own issues and then dealing with the unpredictability of your mother's mood must cause you a great deal of stress.
Mad/Sad does happen (froggy raises hand) but not as a constant state. Usually I'll lash out because my unstable emotions just can't take any more. Usually short lived and I'm remorseful afterwards.
My Mom always said I was an award winner when it came to pitching a hissy fit. Maybe that's why I'm taking meds for my blood pressure.