You mention that this is "triggering." Personally, I think your level of anger is not really appropriate to the current situation. It may be your feelings were triggered from the past, and your anger is really about things that happened in the past, maybe a loss of power?

I don't have a standing appt with my T. He teaches, supervises other Ts, travels a lot on other projects, etc. That's the way it is. I never know when my next appt will be until the end of the session - a week if I'm lucky, maybe almost 3 weeks. That's just the reality of the situation. He does his best to get my in once a week because I've told him it's very important to me. I have a choice to accept this erratic schedule, or find another T. I choose to stay.

Your T has other clients besides you, and they're all important too. I would bring this up with him and tell him just how angry you are, and how it makes you feel. This could be an opportunity to learn something. Sorry you're feeling so frustrated and I hope you can resolve this soon.