This is how my estranged sister would treat us too. She would creep back in when we were at our worst. She'd bait us with something nice, and then, EXPLODE on us. I believe it's a narcissistic tactic. I blocked her in April of 2018. I haven't talked to her since. She has made new social media accounts and has harassed me before, but I just continue to block her.
It's not fun to block someone, but it has to be done. I am glad that you let her go. 🤍