Hi lovingsmk, welcome to the group

we're glad we can be here for you!
So much of your story will ring true to parents here -- one parent being the target of verbal abuse, the cutoff, early signs of challenges, stubborn refusal to engage with treatment, and a seemingly minor conflict leading to a blowup.
It does make sense that while you have tried to treat being blocked as a break, you also miss your D31 and care for her.
Is she your only child? And are you married/in a relationship, and if so, how is your partner/spouse doing with the situation?
Where is your D31 living at the moment? Does she have any children?
...
While not impossible, it seems unlikely that she will block you forever. Many parents here have experienced a child ending contact at one time, but reaching out after a while. Or, even though the child initiated the blocking, sometimes after a while, a parent reaches out to make sure the child is alive and surviving (especially in situations where the parent and child live far apart, for example).
If that can give you some hope, then perhaps you can add another "frame" to how you view this cutoff right now -- not only as a much-needed break from the verbal abuse, but also as a chance to do a deep dive into new ideas for communication. A lot of the tools and skills it takes to communicate with a pwBPD (person with BPD) are pretty unintuitive. In fact, we have a "Tips" menu up top, with a section on
When a teen or adult child has Borderline Personality Disorder. Take a look at some of those articles, and let us know what you think.
Again, glad you're here;
kells76