How do I detach and keep boundaries, but still stay in contact with my mom?

Dad is a narcissist. He's always been one. Our issues go way back. Since he had a stroke, his behavior is on steroids, he's verbally and emotionally abusive. They have a live in aide now, who is more like a glorified companion that gets $200 a day cash. He said if I don't completely take over mom's care, I can't know anything. He sarcastically said you're too busy, you have a child (I do, she's 5). He said I'm the daughter who should be taking care of her mother. He again sarcastically said he has his own "baby" and "issues". He has not set up anything for Mom as far as POA, no trust for her in case he goes first, doesn't care if she goes to follow ups, doesn't care if she refuses care, such as PT. She just refused an MRI in the hospital this past week.
Mom has dementia, fecal incontinence, refuses care, smokes, has gotten so weak she can't walk, can't remember to eat, can't cook, or use the microwave (just a few things).

My husband told my dad he should contact an elder attorney and set something up for mom. I refuse to clean up the chaos he creates any longer. He gets enjoyment of leaving chaos for me to clean up. For example, he has literally said it looks like someone sh*t all over the bathroom, go clean it up. It took me three hours to clean that bathroom. The entire time the house heat was jacked to 84 degrees. I was crying, covered in sweat, feces, and bleach. Yes, I asked him to turn the heat down. He said, "what about me???"
He didn't even tell us the hospital moved her to a rehab facility yesterday. I had to call around to the local ones to see where she's at. He makes it impossible. Just thinking about dealing with him gets me anxious. I wasn't going to participate, just read on the site. Today finding out he's decided not to tell us anything is the last straw. I don't know what I can do, other than be completely estranged.