I'm sorry you had a bad experience there. Have you been diagnosed bipolar by a psychiatrist? What meds are you currently on?
One reason they may have said that about BPD is that most of us BPs are also borderline personality. I don't really know why, but it seems that many BPs have abusive childhoods and develop the abnormal fear of abandonment aka borderline personality disorder. It is not a disease, but a personality disorder, and unfortunately, there is no medication for it.
Let us know how you got diagnosed BP, what happened, whatever you want to share.
Variety is the spice of life, BP is the key