I'm not sure that I even know what to say. I'm sorry that things went so badly for you.

My T told me once that defensiveness comes from trying to protect something. Sounds as if she is doing that about her cancellations. It feels like it's her issue that is interfering with your feeling safe in the relationship. My therapy for the most part was done on the same day and at the same time. He cancelled once (he was sick) and changed a time once, but that was it. Consistency helps you to feel safe and secure. These things are very important in a relationship where trust is the key.

I hope that talking with your counselor is helpful to you. I'm very sorry for your bad experience.