Thank you, I started crying when you said I am not a demon. I baptised myself, exorcized myself and doing all kinds of things spiritual. And no It's not my usual thing. I
Been there. Done that. Got the shirt. It wasn't a demon afterall!
It was scary. It really did seem supernatural, my gf has a masters in Catholic theology, my evil ex wife started texting me over and over an hour after gf walked out. Just too freaking creepy. The only way I feel safe is with Bible being read on YouTube. Her voice went from low man's growl to shrill infant like screaming.
I didn't understand the meaning behind the way she was behaving
Destablization can look all sorts of demon possesed. The person is destablized mentally so no rational thought can occur typically and they are running on pure emotion. Throw in disocciation, flashbacks, and some spiritual beliefs and poof, you have what looks like demon possesion if one is not trained or well educated on what they are looking at.
she has BPD along with her PTSD
I have PTSD and BPD. This actually explains it a lot more. BPD is emotions dialed at their highest. Anger becomes rage. Sadness because suicidal. Ect. A severely destablized BPDer can rage like they were demon possessed. When I would rage at my dad and/or step mom, my dad commonly said I was demon possessed or had a demon in me. If you add in the other stuff above but add in highest extreme of emotions possible (like rage) and yeah, looks a lot like demon possession but it's not.
Certian meds can make the destablization worse. And like
@EveHarrington said, completely numb for a time before the destablization. It took me years to find the right med that will help to stablize my emotions, bringing them closer to normal. Not normal but closer to normal.
The meds themselves actually don't do it all. I actively work DBT (I have a workbook) when I start to destablize. Those skills are paramount to keeping me stable. DBT is the number one therapy for BPD.
If this diagnosis is new for her, give her time to work through DBT. It can take a great deal of time to start applying the techniques to your life and and learning how to.