Hi jq46810,
Can anyone explain what she is doing.
To answer your question jq46810, BPD is a persecution complex; blaming and victimization and not taking responsibility for their lives and you have a drama triangle.

A pwBPD will often cast themselves in the role of victim along a triangle and sometimes cast themselves in the role of persecutor or rescuer and cast others in the role of persecutor, savior and sometimes we shift to the role of victim.
Last Thursday I received a text from a stranger saying stop harassing her she is getting on her feet leave her alone, I haven't called her once in 4 weeks.
The stranger that sent you a text last Thursday may subconsciously be rescuing your ex or cast in the role of savior and you're cast in the role of persecutor in this polarized dynamic and you are triangulated.
You had an argument with your ex and she called the police and filed a domestic charge although nothing happened. Calling the police is a quick way to triangulate someone and she's cast in role of victim.
I can relate with how distressing this all feels. My ex once charged me for domestic violence charges as well and I was triangulated when she started an affair with her boyfriend, he was her savior and I was her persecutor and I was at the lowest point in my life. I would like to echo SGraham. We're here to help.
I agree with Lucky Jim and that it's in your power to collapse this drama triangle.
Your ex sees people as either "all good" or "all bad" and not as an integrated whole or the grey area in people with both good and bad makings. Her perspective fir the time being is that you are all bad and persecutor.
I also agree with Lucky Jim that it's a good idea to self protect with low contact or no contact while you're split black to heal your wounds and detach to start feeling better.
The advantage that you may not see now because you may be knee deep in pain is that her rescuer is keeping the chaos and drama away from you and you can take your power back with getting off the emotional roller-coaster.