I've been told I'm difficult before we had the diagnosis of brain injury.
I've felt helpless, powerless, and I questioned myself about my human value.

Now, I can conceive that not knowing about brain injury can be very frustrating from a T. However, it's doesn't excuse such behavior from a T, and any health-care professional anyway.
IMO, such judgment from a T about a client speaks volume about T's hypertrophied ego and sheer laziness.