Where to find help with a mean elder whose an abuser of a caregiver adult child?

adult child caregiver of mother? who is mean and cuses her daughter who is trying to clean and help her but daughter gets cussed out and mother will poop in her diaper and play in it and thro it all over the room etc. how and where can I get help? ,Mother is bed ridden and cant walk or sit along. Daughter does everthing for her.Mother cusses daughter out all the ttime and tells her she is no good. mother is 90 and a hatefull old woman has been all my lifeshe has dementure and lots more