IMO (both professional and personal) the term of borderline personality disorder came into being because of symptoms doctors saw but refused to "believe in" Multiple Personality Disorder/Dissociative Identity Disorder...and they needed to "put" the patient somewhere so they could be paid for "treatment."

Or it might be used by a doctor who agrees with the DID but hasn't seen at least 2 personalities/alters/ego states (whatever terms they decided to use) yet.

In any event, YOU are still Whom you are! A different term for your behavior won't change for you, it will only change for your treatment program plans...and any T worth their salt (again IMO) will tread gently in these matters anyway.