Why was she your best friend? Sounds to me like you should take this golden opportunity and say good riddens.
P.s. if you do she will probably realize that she has lost all control over you and try to regain your friendship (in order to regain control). Verbally kick her in the shins and leave it at that. She had her chance, she dun messed up, and unless she realizes her part in the situation she isn’t going to be worth having around. She is a toxic friend and you aren’t doing ether of you favors by putting up with that crap.