1. Just because someone contacts you doesn’t mean you have to respond.
2. You have to look out for yourself. If you don’t, you will be of no help to anyone.
3. You are not a professional. This is clearly a mental health disorder she’s going through. By playing into her dysfunction, you are actually contributing to her disorder and making it worse.
4. Her throwing tantrums because you set boundaries is a good thing. That means what you are doing is working! Eventually she will collapse in exhaustion and figure it out. Dare I say, act like a human being.
5. You are not dealing with your ex as person. You are dealing with a disorder that has taken over her being and personality. It is not her. She is possessed.
6. Take some time off. Block her email and numbers. Move if you have to. She will get help, get better or find another victim.

So much here! But start with this.