Partner’s toxic stalker ex GF causing issues – help!

My partner has a very toxic ex gf who faked having cancer, took money, cheated, physical fights etc.

Since they broke up, she sends manipulative messages like “I’m so lonely if you dont answer I’ll harm myself.” To nasty texts, phone calls etc.

I’ve always said handle it the way you think is best because he knows her and I dont. I’ve been supportive and tried my best to understand.

However, he has moved 2 roads away from her now and she found out because she was stood outside his street and saw his window. She calls him and he tells her he’s in a relationship, she goes insane.
She asks him why he hangs out in road “xyz” (this is where I live) and named the parking lot of the mall he went to. How does she know?

I come over and shes sat outside waiting for him and shouts at him because she asked him to promise not to bring me over until she is comfortable. I didnt know this.

I kept cool and said it must be tough for him but now its been a week and I’m genuinely upset that an end hasnt been put to it. He doesnt want to report her.

He is now angry at me for telling him I’m not coming over until the situation cools off and is sorted. He said I’m blaming him, being rude, the situation is out of his control and has anxiety because of her. He said “You just want me to fight her and end up in jail” “You’re doing this cause you think Im nicer to her” “You think being stalked is easy I hope you never go through this”

I dont understand what to do?
My message was firm but not harsh or rude.