Is she is capable and safe to leave on her own - you need to live your life and not let her manipulate you.

Can you just split if she goes off on you?
Give her cool off time - like a child?

Some ideas?? maybe?
make a contract with her - or just a list outlining some basic adult house rules?

Is there a caregiver support group in your area?
it must be so difficult to deal with her...