How to cut off your mom?

I should have cut her off a long time ago. This woman has been nothing but jealous of me and out to destroy my life and my marriage. She wants to be me in a way that's extremely creepy and I'm done. I can't have her in my life anymore. I just need to know how to properly cut her off. I've never cut anyone out of my life and the fact that the first person I'm cutting out is my mother is stressful.