Is it ok to stay away from an abusive negative mother living on her own?

Once again Mom has accused me of not being there for her, abandoning her. And now stealing from her bank account. Last time she said that I started a journal of every day I had come to visit her, or do errands for her or drive her around. It's endless and my journal is full. I work a full time job and luckily I work from home for the company so I had the internet installed at her condo so I could work out of her place once a week, make her a meals etc. I take her out twice a week, have arranged for a cousin to also take her out (I pay her), have hot food come in twice a week...which she says is "garbage". She keeps wanting to cancel it but she can't cook except for scrambled eggs and toast. I had it coming in three times a week, but I cancelled the Friday delivery to plan a routine with her to take her out to dinner myself. People who know her ask me how I do it, dealing with her all the time and I say she is my mom, I have to...but she is mean and nasty. No one in her building likes her. She refuses to acknowledge my husband (jealous), calls him names,..so he never goes over now or does odd jobs he use to for her. She never says she loves me after I kiss her good-bye each time and say "Love you mom"..she doesn't respond, but tells my only sibling brother out of the country that she loves him on the phone... I laugh actually every time I hear her say it. She lost her drivers licence due to her memory and blames me because I took her to the doctor..he saw something not right with her so he tested her...I could go on and on...but the last straw was last Friday when she was mad at my brother for not bringing her down to his home in Florida (he doesn't want her there after she yelled obscenities to his wife) again jealous of any of our partners...so she took it out on me. I had enough, told her so and she went ballistic, told me to get the F out of her house and a whole bunch of other obscenities and accusations that were not true...She has dementia, no doubt about it but she is smart and knows how to cover it, for a bit then people catch on. She needs to go into a home but she refuses. She isn't hurting herself, she is just existing. But I can't go back..and she won't change, but I worry about her, wish things were different. She could have a really good life with us but she only wants me around to do her errands...She feels everyone owes her. Thanks for letting me vent here.