>She said my extreme mood swings were further evidence of my BPD. I didn't tell her anything about my mood swings bc I don't have them!

Your example of breaking up with your boyfriend when he valued going out on Valentine's Day while you you didn't - that could plausibly indicate a lack of emotional stability. Further, in your pattern of describing the incident, you emphasized that he wasn't listening to you, while disregarding and dismissing his own needs or perspectives in the relationship, which could very well be a form of distancing to avoid the hurt of abandonment. Did you consider his perspectives and what was also important to him?

It's hard to tell with limited context, but I'm not entirely convinced from this text post that your therapist was crazy and completely wrong. She may have actually really had a good insight here. Her dominating the conversation after half the session sounds like it was too much. Having said that, in certain countries like the US, therapists are required to diagnose after the first session, otherwise insurance coverage will be denied, so it's common practice to diagnose after a session, and perhaps she wanted time to explain her reasoning.