I’m going to delete this post a little later, but in a similar situation, my ex, who had already bitten me very deeply a few minutes earlier on the neck/shoulder such that blood was running down, began to transform from one mania to another and began hitting herself in the face and head with a phone (you remember telephones?!). She was screaming “what is wrong with me!? I just want to die.” It ended with me sitting on her chest pinning her arms and her still trying to bite me. You can imagine I have fear, anger, sympathy, pain; my HR and BP are a million; I sort of bounced on her to knock the breath out of her, which worked and then she just curled up and sobbed for 30 minutes, and more or less came back to normal. Interestingly, she forever held against me that I had hurt her that way, and told some of the story in a slanted way, but she had for-real bruises on her face from the phone, but never ever said a thing about that.
We’ve been divorced 22 years, and what’s interesting about my just now recalling that particular night is that I have a lot of sympathy for her and the difficulty she had just being. I actually wish I hadn’t hurt her in any way, even under those circumstances.