Gaslighted in therapy?

Maybe this is too strong a word....but there have been a few times in therapy where I've been gaslighted with sessions. Correct terminology? For example, just this week, I see T for the last time in her current office on Wednesday. I also saw her yesterday, to which she told me "see you tomorrow!" I said no, Wednesday. She said "that's strange, I have you down for tomorrow." I said that is NOT what was scheduled....but she never admitted to changing it around on me. Like I am to believe my google calendar, AND my paper calendar, and my memory are all wrong? I remember the conversation, and I also remember her saying just last week that I would be her last client in that office ever, with my Wednesday session.

So, I'm supposed to see her again today. I plan on canceling. I hadn't planned for two back to back sessions, and just not happy that things just got switched around without asking me, and then as if making me feel crazy that it wasn't the way I knew it was???

It's devaluing, disrespectful, and as I see it, yes, a form of gaslighting.

I think you should go, instead of canceling, and discuss all this, including expressing your anger. Cancelling is not going to do anything productive.
You may find that when she said "that's strange" she was referring to her own behavior. She might not have even thought that you were the one who made a mistake.
I seriously think you should discuss this with her.
To me this seems like the kind of misunderstanding that can happen a lot in therapy, and it seems to have stirred up a lot in you, and talking all that out could be very useful.

Sounds more like a scheduling snafu and her own confusion about days and times than actual gaslighting, but certainly discuss it with her if it is bothering you.

From the info you have shared here, it does not necessarily sound like gaslighting and could just be that she put down the wrong day in her calendar in the first place by mistake and got confused. But if she has these tendencies in general, then it's definitely important to bring it up, I think.

My first T has issues similar to your concern. He is pretty bad at administration and remembering/recording practical things correctly but does not seem to be doing much to help it. We had a standing appointment same day and time each week so that wasn't a problem, but canceling was. He claimed not to remember my advance cancellations and called me on the phone three times, asking where I was. When I complained, he said that I should remind him the day before. The last time this happened, he kept saying I did not cancel the session. Also, he messed up the insurance claim form several times in a few ways. He typically did not apologize for these things even when he admitted it was his mistake, and were often defensive. Then interpreted my anger about his messing up as displaced anger that I had for my mother. He was generally very open to discussing my criticisms but did these things in the moment many times without acknowledging or apologizing. Of course I was annoyed, and not at my mother. I don't think that the situation has deeper meaning for me in this case, I was just reacting to his messiness.