Yes, focusing on ourselves is good way to go forward. When we act in a manner consistent with our beliefs and values, that's coming from ourselves. Sometimes this process of a relationship with pwBPD can help us investigate beliefs that we previously took for granted.
I think you're right, I do think the path is not linear and it takes time.
I hope this helps with the rumination. If you're finding yourself stuck in a judgment cycle of yourself and ruminating--you can try writing it down. This can sometimes help in moving forward.
I do think that off this forum you may feel a lot of the 'get over it' sentiment. I found that people off this board don't understand. When I explained how my ex fit the DSM criteria, I was mostly met with "oh okay, I can't relate to that" sort of thing. It basically stopped conversations. So I too feel understood here.
I want the truth of her character to be owned by her.
I share once removed's familiarity with this statement. I'm looking forward to your thoughts from here.