My mother is insane. Seriously. She has long periods of lucidity interspersed with intense manic episodes filled with psychosis and delusions. I don't have a Mom either.
But I have great friends and older women who act as mentors in my life, and I am grateful for that, even on the days I feel most bitter and lonely for my Mom.
I try to accept the good days/months as they come - she is very smart and funny - and stay away from her on the bad days/months. *We haven't spoken in almost 7 months now from the last episode*
It sucks. Big hugs to you today, you have my complete empathy.
~T