emjay45151,
Glad you found us!
It certainly seems have you have had some very difficult times growing up! I must say though from reading your post you sound incredibly wise, brave and mature. It sounds like you have learned a lot of great techniques to use to improve upon the relationship with your Mom and most importantly take care of yourself.
I would like to comment on you feeling doubtful about an official diagnosis. So many of us, myself included, don't have an "official" diagnosis. That is not important. What is important is that you have recognized BPD traits in your mother, (that is why you are here) and it is also important not to doubt your own feelings!
If you haven't already I invite you to read and post on the
[L5] Coping and Healing from a BPD Parent, Sibling, or Inlaw board. Members here can relate to so many of the things you are feeling. You can learn more about setting boundaries, finding relief from FOG, encouraging self-care, improving your handling of relationships impacted by your BPD relative, and pursuing a path of recovery from traumatic experiences.
The validation, information, and support will give you strength on your journey.
I think it is wonderful that you have your sister as support, does she live close to you where you are able to see her often? Also, it is great that you have an opportunity to explore therapy. It is easier said than done, but starting therapy was one of the best decisions I have made in my life. That and reading and posting on this Board have been a tremendous help to me!
Bananas