I would recommend not talking to her but messaging her and then muting her

Think about what you want to say, keep emotion out of it. Be factual, strong, clear. No negotiating, no waffling. Just a very clear this is what is going to happen. Then there's zero contact or interaction until you feel strong and ready.

To some degree, she still has control. Take away her control over you.

People often confuse what the opposite of love is, it's not hate --- hate means you're still invested, you're still wasting your thoughts and energy on them. The opposite of love is indifference --- that means that you no longer care, think about, or allow them to have control.

Reach the point of indifference and you'll find the peace you want.