Lizzie, I'm so sorry this is happening to you. My Nmother followed a very similar path. She never ended up in a nursing home, she had a live-in caregiver, but she peed all over her furniture and her bed and turned the home I grew up in into a filthy reeking horror... the caregiver spent all her time cleaning up after my mother's messes. It was like "Dolores Claiborne", that Stephen King novel, for the poor woman. She actually tried to defecate in my car, once, when I took her to a restaurant and we had to cut the meal short because I lost a crown from a molar and needed to get to a dentist pronto. All the way home she was sitting there straining to try and soil my car seat... needless to say, there were no more trips in my car after that. [Car was fine, she didn't manage it.]
Her attention seeking did eventually kill her, she had herself hospitalized over some trivial thing, trying to compel attention, and caught a fatal superbug. The worst thing is, all my regret about her death was that there had never been a person there, never been a mother there, not for me. Not ever. Other than that, what I felt mostly was relief. Of course, she left a horrendous legal mess behind to be cleaned up... but she's been gone for years now, and she will never be able to harm or drain or slander or parasitize me again.
I was only able to forgive her after she died. As long as she was alive, she was intent on harming me, and that was something I could never forgive while it was going on.
So I feel for you, because it looks as though your mother is headed in the same direction. She just has a lot more people to jerk around with her attentionseeking, before she gets there. And you can't win on this. If you stay away, you're a 'callous, unnatural daughter'. If you don't stay away, she'll drain you dry, and discard the bones. You have to define 'success' as surviving with as many of your resources intact as you can manage, and don't expect other people to understand or care about what you are dealing with.
You might want to consult an elder law attorney. I lived in dread of my state's "Destitute Parent Law'. I could have been compelled to spend my earnings and my life's savings on my Nmother... my state has that kind of law on the books. Fortunately, either my mother never knew about it, or didn't live long enough to come up with a way to go after me, by using it. She woulda, if she coulda.