Why are breakups with borderlines tougher?

Only if you agree or relate of course. Honestly, I am kind of new to this disorder and learning about BPD. My therapist told me that the breakups after being with a Borderline woman in my case are more challenging. I recently discovered she had it after all this time, so much fun...right? I specifically had to get therapy because I couldn't control my need to text her unlike my other exs in the past and I feel shame and disappointment. That's not the person I am and can't recognize myself.

I haven't found anyone that I feel the asme intensity and chemistry mentally or sexually, they're good people though, it's not them. Knowing your thoughts about post breakup experience is appreciated.