I wonder if it's something a bit different than not enough progress. When I used to work with young people on their first legal jobs (as a mentor), I could identify the difference between those who were stuck in their ways of being and those who might also be stuck or struggling with something, but they had potential. Seeing those who had potential but weren't able to improve and trying to work with them-- I was always pushing them. The ones that didn't seem to have much potential, I just really didn't try that hard. I was accepting of the ones, sometimes more affirming, than those who I thought could do better. My most contentious relationships were with those I perceived could do much better and become better professionals. Maybe I was wrong about those judgements, although after doing it for 25 years, I think I was pretty spot on.

So if there's a parallel to T's, I think it may not be frustration with a lack of progress as much as the difficulty of seeing those with potential not living up to it. And/or maybe it is about how he wants to work. I don't think it's unreasonable for a therapist to decide to end therapy if there isn't adequate progress made; some would say that's the only ethical thing to do. Then maybe it's a fit issue, although I think you've said before you're unwilling to try another therapist, but if you have goals that are in conflict with his idea of progress, it seems like you are setting yourself up for frustration, which you clearly feel. If you're not willing to see someone else and he's insisting on the traditional kind of progress, then it makes sense to me that there's a lot of frustration that you'd feel.