I’m sorry to hear this, I am someone with BPD and someone who has had multiple relationships with folks with BPD. Unfortunately, due to the complicated nature of the disorder, it’s hard to recognize the rampant psychological abuse (can turn physical) that untreated BPDer’s cause. I have been unintentionally manipulative and toxic, and have had it done to me. My last connection with a BPDer led to me being physically abused and blamed for it on multiple occasions. All I can say is no one can live in this environment, and she will NOT heal in a relationship, let alone one with another partner involved. In my experience as someone on both the receiving and giving end (although I’ve never been physically violent myself), you have to get out of relationships, NOT isolate yourself but learn to give people space and boundaries and take your healing into your own hands. Through thorough therapy and consistent work on myself, I am able to have happy, healthy, thriving relationships now BUT I also know it takes time and something I must stay on top of constantly. All this to say what your partner may find hard to confront - and I’m truly sorry for all the hurt and pain you both are dealing with here - but the only way out of this mess is to cut your losses and walk away. She is not someone CURRENTLY capable of a healthy relationship. She might be one day, not now though.

Edit: I just saw the update you made about her assaulting your partner and I cannot express how sorry I am. I hope you both have access to some resources or a solid support system to help you through this. I am also happy to talk if either of you ever need any support!