Overbearing mum

My mother is a text book narcissist..My sister has zero contact with her & I try to keep at a safe distance. I am a independent 51 y.o woman, who is struggling, again, to deal with her nasty & interfering ways. If you don't agree with her on any subject, she attacks you verbally. Christmas day, I walked out of her house, when she started pointing her finger at me. She is negative, critical and is always throwing me under the bus, with my children. When she comes to my house, she literally goes through my stuff, pointing out dirt, if any, on the floor & asking me who the presents are for under the tree, even though they clearly are not for her. She is a gossiper. I cannot deal with her harsh, nasty comments. I have just gone thru a terrible relationship break up & I just am to vulnerable to be around her. Any tips?