Mine used to be unable to give me a fixed slot as she had way too large a caseload, plus I had some scheduling limitations placed upon me by my job.

I would only be able to book the next appointment with her, rarely the next two, and even though i knew that was the case with nearly every patient (because she said so), it was affecting me negatively.

But she listened when I told her it was hurting me to see her just once a month, and that I didn't want ro do any trauma processing at that frequency.

She then tried her best to fit me in at our agreed upon twice a month, usually a morning appointment as that was a condition my job imposed.

Now that she moved to private practice, and I'm currently not working full-time, she's given me a set day and time even though my schedule is now extremely flexible. She tries to avoid changing it unless she has no other choice, even though I tell her I'm very willing given my flexible schedule.

If i were you, I'd consider telling your T outright how this is affecting you. If she's decent, she'll listen and at least explain or try to meet your reasonable needs.