hi downnout98,
What do you think from your experiences?
Breakups happen and rebuilding relationships is possible. If there is a longer history of similar break-up behavior in her past then of course the risk of repeats goes up.
I am not real sure what to tell her. It seems like when I have set boundaries before, it would drive her nuts. She gravitates to those that give her the most attention, but then complains when there is too much attention or what becomes perceived as needy. That is how the other guy came into the picture. We were working on our issues but then this guy came in and gave her all the attention she needed.
People in general and pwBPD in particular like validation and loath invalidation. When a relationship gets into a crisis the invalidating messages between the partners increase and the validating ones become more rare. A healthy relationship has a ratio of better than 5:1 between validating and invalidating exchanges. Now attention is quite validating and easy to give at the beginning. It is also easy to validate that the other has problems with a third party.
But then attention is not deep understanding. Validating third party trouble is not as deep as validating the true nature of the relationship between two people f2f. You are communicating so there should be opportunity to validate your understanding of what is going on - crisis, insecurity, not knowing how the relationship between you two develops, past upset, good memories etc. .
The issues we were working on were allowing me to parent my child, splitting time between us and the kids and time for myself.
That sounds a bit like problem solving. Note that problem solving like marriage counseling tends to be a bit invalidating. Her needs for attention are infinite and part of managing that requires validating her frustration and not giving her all the attention she craves. Trying to strike an agreement is just feeding the conflict. Managing your attention is your business. She may give input but you decide. Dealing with BPD requires balancing validation with strict boundaries.
Rebuilding your relationship will require taking risks including the risk to be hurt. Boundaries are important tools to manage risk exposure. Can you imagine a step wise approach to re-connecting with her? What risk are you willing to take in the first step and what are the consequences for yourself if boundaries are crossed?