Try taking to her first, if she’s still being rude or blaming you for anything and putting the problem on you, then drop her. this means you are in a toxic relationship with your friend and it becomes overwhelming. i’ve been in situation like this. if it’s that bad, then just leave her, you’ll feel much better.
I would say that if she is being mean you can first try to talk it out with her (because relationships may take work sometimes and if she is really important both of you will be willing to put in the work), but if that doesn't go well and you really don't think it is going to work you should go to your other friends or family for support especially if she was a very important part of your life.
