Could it be that he did “just” forget? It’s devastating, whatever the reason, though. Once, I was halfway through a session in which T and I were having a conflict and he said, this is terrible timing but I have to tell you I am out next week and forgot to tell you. I promptly burst into tears and explained that I would’ve handled the session totally differently, had I known he would be out. He has been much more diligent about giving me notice since then. We talked it out when he got back and he was able to rebuild my trust in him.

I do hope when he comes back you will talk through your (totally warranted) distress with him so he can hear how it affected you and give him a chance to help you feel reassured.