Regardless of diagnosis, the therapist remains the authority. If she is incapable to dealing with someone of a certain diagnosis or with particular traits, then it is her responsibility to recognize and refer out if needed. Furthermore, it is her responsibility to define boundaries and to enforce them in a way that is both effective and skillful.

Your responsibility is to focus on whatever your goal is with regards to therapy. The boundaries you learn to respect are the ones that are clearly defined and yet, she should be skillful to redirect you when you encroach on them.

As for the confusing bit, it's one thing to walk away, it's another to walk away with a fireball behind you because you just blew something up. In this case, I think the most effective thing to do is to walk away without the fireball. Don't leave the door open, don't be passive aggressive, don't find a way to ruin her. Just walk away.

Then, from there, find another T and process what happened. Perhaps a complaint needs to be filed. Maybe not. Having someone with whom to check the facts will be helpful.

A diagnosis is useful in some ways and in other ways, it's utterly useless. Don't define yourself by what "BPD people do." Define yourself by what you do and who *you* are and look for a T who is going to treat you as an individual and not a diagnosis.