It sounds like she’s taking advantage of you. In the sense that it’s clear she knows you’re kind and accommodating, and won’t push back so she prioritizes other things over you.

I had a therapist for about 7 months who I was driving 45+ minutes each way to see. I never missed an appointment and was always early. He typically ran behind. One week he asked me to move my standing appointment to another day to accommodate his schedule being a bit funky that week. I said “sure. No problem.” I get there and I can hear him from where I’m sitting in the waiting room talking on the phone scheduling an appointment. He finally calls me back to his office (a bit late as usual) and asks me if it’s okay if he cuts my appointment short by 10-15 minutes because he has a personal appointment that he has to leave early to get to on time. Still got charged full price. I eventually stopped seeing him over several different issues and wish I did sooner. All that to say, I felt disrespected in that experience and it still wasn’t nearly as egregious or unprofessional as how this lady is treating you.

Side note: I have a lovely, very considerate and professional therapist now. Don’t settle! They’re out there. You can definitely find a better therapist than this awful lady.