Hi SufferMySister,
I want to join
busybee1116 and welcome you to the BPD Family. Good for you taking care of you Self-care is important particularly when you have a pwBPD (person with BPD) in your life. You have set a boundary to protect yourself from verbal abuse that is a good thing, a healthy thing for you to do.
I know this isn't the way you want things to be with your sister but we can't change others we can only change ourselves. You can't change, or fix your sister but you can change how you interact with her so that it works better for you. That is what boundaries do that is what you have done by cutting back on contact with her.
It sounds like your sister is using FOG (fear, obligation, guilt) or emotional blackmail to try and boundary bust. Here is a link to some reading regarding FOG if you want to read more... .
https://bpdfamily.com/content/emotional-blackmail-fear-obligation-and-guilt-fogI also wanted to point out the box to the right --> Everything there is a link to more information. You might want to check out the "Lessons" section when you have time.
I encourage you to continue to post. There is a wealth of knowledge, experience, points of view and support here.
Again Welcome
Panda39