Hi neff7396 and welcome. Thank you for sharing your story with us.
I’m not sure how to get her to get a handle on her disorder.
There is not a lot we as "nons" can do to help people with BPD or BPD traits to get control of their disorder. What you can do is educate yourself on how
you may better cope with and respond to her behaviors, such as setting boundaries. In the best case, this might put them on a path to self awareness and possibly seeking help. In the worst case, we at least become better versed in self care.
There are two ways to accomplish this here. First is to start looking through the excellent skills workshops on the right, which are helpful for coping with any kind of relationship challenges.

The second is to post on other members threads to gain context on your own.
How are you practicing self care when things get chaotic?
Sending you strength,
RolandOfEld