I'm going through this right now
All I can do is deal with it and hope my marriage stays together, since my mother is living with us until we get her well enough to go home (not likely) or moved into assisted living.
My mom's been seeing a Psychiatrist for years and years but I'd gotten to the point that her mother, sisters, and friends can't deal with her anymore. So I drove the 200 miles to her small town, picked her up, brought her to Houston, and took her into the emergency room at one of the Medical Center hospitals. 2-1/2 weeks later they release her to me for outpatient care. And then the fun really began.
What really drives me crazy is when she's down she can't do anything but stay in bed and then almost as quick she's really up and can't understand that she needs to make some decisions before she's down again.
If you're still of child bearing age... have more than one child. I'm an only child and it's really taking it's toll on me. Of course I realized this little tidbit after having only one child.
I've been resisting bringing any of this crap up on here, but I'm about on the edge of sanity myself at this point.