Welcome
HQP!
Thank you for joining our family and for telling us a bit of your story.

How stressful it is to have to deal with family after a loved one has passed, especially when there is suspected dysfunction. The loss of a loved one is enough in and of itself. Then to add the squabbles over inheritance issues only adds to the burden in a way so wounding and hurtful. I am so sorry. Holidays only add to the load.
You mentioned T. Have you started yet? I hope you are able to find someone who is familiar with BPD. I see a T on a regular basis who is helping me work through what I experienced as a child of an uBPDm. It certainly has helped me a lot, and they can often see things which we cannot.
I think you are doing a good thing by some of the actions you took such as leaving the area, speaking to him about his behavior, and setting up space between you. While it is hard to do, you do need to take care of yourself above and beyond the demands and obligations you feel he puts upon you. Self care is very important, especially to help you recoup emotionally and physically.
Have you read any books about BPD? Do you suspect that is what he may have or has he been diagnosed with it?
Please jump right in to reading other posts and offering your opinion and thoughts too. We are family here and support one another because we understand.
Wools