Poisonous family...do you feel guilty if you put some distance there?

My sweet ole mom is 91 and I live 10 minutes away, but she is so manipulative and self-centered, I get really upset with the games. I can not reward the negative behavior and try to discuss it, and how it affects me to no avail. She has others to watch her, but I feel like I need to back off for self-preservation. I feel horrible.
She tells me she’s bed ridden when she is not. and I usually see her every couple of weeks. she wants much more of me. I call every day. I feel like I have done everything for her and now I have nothing left. What do I do?

I usually dont cry, but now 2 days in a row….i’m a weepin willow.