Hello golden and
I'm am sorry you have had to deal with your son's demands and blaming. I'm sure this has caused a fair amount of drama, heartbreak and guilt. When a child (even an adult child) suffers from BPD, it affects everyone who loves the child. But you've come to the right place for help!
As you read the information here you'll see that there are things you can do. A great place to start is by reading this:
What can a parent do?. I also suggest you go to the discussion board:
Parenting a Son or Daughter Suffering from BPD board to join with other members who understand what you are going through. As sparrowfarfrom home says, you don't have to explain much here; people will just "get it".
What are some of the behaviours that have you suspecting he is BPD? Have you noticed a difference since you started using SET communications?
Welcome again and please keep posting so we know how we can help.