You are allowed to terminate your relationship with toxic family members. You are allowed to walk away from people who hurt you. You are allowed to be angry & selfish & unforgiving & don't owe anyone an explanation for taking care of you.
We repeat family dysfunction. I came from many generations of alcoholism. When I was a little kid I wanted to be different than my dysfunctional family, but I ended up just like them. Once I did become clean and sober I ended up being the black sheep of the family. Some family traditions are meant to be broken.
They will say the most awful things you'll ever hear. They'll turn everyone against you. They'll intimidate you, and inflict fear. They'll try the best to ruin your reputation and isolate you. The best thing to do is to walk away from the Narcissistic Beast. They don't deserve you, going no contact is the only way to beat them, and for once you'll have one over them.