In my opinion you have done the research and it’s pointing to BPD

Can a person with BPD have a healthy relationship? Sure but it take enormous amounts of work on that persons shoulder.

DBT is the standard type of therapy for BPD , most Therapist have groups that are 6-12-18 months long, weekly with lots of hard work.

My best friend has Bipolar like me and BPD, she got sick of feeling broken so she committed to DBT 12 months, she worked her self to the bone to change her reactions and thought process.

She’s got a handle on it now , does something pop up here and there? Yes, but she has coping skills to fall back on.

I’m not saying this woman is a lost cause, everyone deserves love no matter how messed up we can become ..... but if it were me I’d only agree to taking things slow and you seeing her work on herself, you can be supportive, but the hard work is on her end.

Honestly I think it would benefit you to see a Therapist to process how all this had effected you and to get advice from a professional about what needs to take place for the possibility of you two staying together.

Good luck