I understand. My ex therapist used to promise she would never, ever dump me, never abandon me because she knew i had such severe abandonment issues, that when i left therapy would be up to me, etc. Then after 7 years of promising that, she dumped me one day. I still have no idea what i did wrong. She had made so many promises. I was very upset.
I think it is reasonable for you to be upset. She shouldnt have made those promises.