A therapist is a good suggestion from the above poster. I've been going to one for 3 years now and it really helps. I've also reached a stable point with my bipolar and found the right meds, but my therapist is there every other week to help keep me grounded.
I also find that talking to my Mom only makes matters worse. She doesn't have a clue about Bipolar, however, she thinks she's a psychologist, when she's just an alcoholic who likes to diagnose everyone and find solutions to their problems.
My therapist told me to lock myself in my bedroom for an hour to read a book or in the bathroom to soak in the tub, to get away from my stepdaughter for a while. Tell the kids this is your time and you are not to be bothered and just relax. You do need time for yourself.