Has anyone managed to rebuild something stable after this kind of breakup or rebound?
My 24 year marriage to my BPD ex fell apart suddenly and she walked away to pursue another man. I started long-distance dating almost a year later and I was also surprised that she was jealous because she told me that she hoped I'd find someone.
While we never reconciled, we did find friendship once again and were able to heal the past wounds.
How did you know it was different this time?
Part of a BPDs relationship cycle is this exact pattern- discarding someone and then coming back to start the relationship all over again. I've seen this with my BPD ex wife and my BPD daughter more times than I could count. I don't think it's a matter of "is it different this time" as much as it is "could I be different this time."
The reason I say that is because you know what BPD is now, you understand the basic triggers, and you have better strategies and coping skills to work through conflict. What will make things different is how you respond when she's in crisis to keep trust levels high and avoid the worst of BPD tendencies.
Think about it- does your ex have any long-term best friends or family members that they're super close to? If so, that's proof that they can maintain stable relationships despite having mental illness. The "x factor" here is more you than anything. Does that make sense?
For me, I look back and feel confident that if I waited things out long enough, I could have reconciled with my BPD ex-wife. I decided on a different path after weighing the pros and cons, and I don't regret that decision. My journey is very personal and unique though, and yours is as well. So general advice may not be particularly helpful for your specific situation.