Why would ever contradict her? “It’s your fault!” “Yes. I did it. I poisoned you.” “Don’t mock me!” “I’m not. I really did poison you.” “…” “…”

Her blaming you is like a kid that keeps asking “why?”, but a lot less wholesome. She wants engagement. Don’t give it. Do not bicker, do not engage in good faith dialogue (she isn’t), just go “yup”, “that’s right”, “um-hum”, “you’re right”. And when you eventually had enough, get up, leave, don’t acknowledge that you’re leaving or say goodbye. And absolutely, do not ever pick up the phone from her, ever. There really is no situation in which picking up that call will leave you better than before.