Welcome DarcyMB!
Sounds like your family has had their hands full for quite some time. I'm very sorry that you have had to struggle with this. Dealing with a BPD family member makes all of life so complicated whenever you need to deal with them. It sounds like you are taking the right steps through educating yourselves and upcoming therapy. Kudos to you to recognise that there are things you can do to help.

In addition, joining us here will provide you with lots of helpful information plus the freedom to ask questions and find listening ears as needed.
My mom was an uBPD. She never thought she had a problem as most BPD's don't. You will need to learn to establish boundaries when appropriate, and remember that the boundaries will be for you as a BPD will not respect them. Value yourselves and your own health.
Have you read any helpful books about. BPD? There is a book section here at BPD Central where you can find good reviews on books which have been helpful to our members. The list to the right is a great place to start digging deeper into understanding BPD. --------->
How soon do you have your first T session? Do you know if the T is familiar with BPD?
Keep us informed!
Wools