In my heart I can't say that I love my parents and wish to continue a relationship with them. I am thankful for the good things they have done. This is where my guilty conscious comes in.
I think we all struggle with that. Many times our BPD parents have done unspeakable damage to us as human beings, usually emotionally and not physically. But then at the same time they are often great people in some ways. Generous, lots of friends, speak highly of you. You can also look at the circumstances of their lives and feel sorry for them. They probably came from bad places just as you, as their child, now have. And people will remind you of the "good times." "You know, your mom loves you so much. She would have done anything for you." Right.
What I've come to think about is at some point you just have to judge a person by their actions. And you may have to put aside your parents' feelings. Of course you are a decent person and you want them to be happy! But do you want to sacrifice your well being for them? It sounds like you don't, and that's fantastic. Love yourself first. Having parents like this puts us in very difficult places, places no child should ever have to be.
Do you have a support system in your life you can lean on? A significant other? A sibling? Good friends? A therapist? Sometimes it can be helpful to have someone who cares about you, in some cases maybe they care more about you than you do yourself. If they can really understand your situation, maybe they will be a good sounding board and be strong for you.
Maybe that isn't the healthiest thing... .But it can be a good tool.
I am not in your real life and because of the limitations of the internet I can't say "GeekyGirl, no. Don't answer the phone, don't let them back in."
Good luck and lots of love to you... .