If you try then you have hope and when you have no hope you stop trying. My T has spoken in the same way and still helped me in the end. Stuck now doesn't mean stuck forever. It does sound like a complicated situation with her mentioning things and not following through with them.

My experience has been that the most important thing in therapy is staying to work through these things. I hope that your therapist is actually competent enough to help with that, because it can be so healing. Perhaps it would be a good idea to try taking your letter with you to your next session where you can really discuss it openly and honestly.

I'd say most us (probably all of us) responding to you have experienced pain as a result of therapy. I certainly have as a result of my therapist's mistakes and really relate to the big feelings it can bring up. Not that long ago one of the many mistakes I felt that my therapist made was apologising for her mistake (forgetting to call me the first time in four years when I'd reached out in between an appointment and used the word 'desperate') by saying "I'm sorry you feel so hurt and angry". I was pretty annoyed when she tried to apologise for my feelings and not her mistake, in the middle of so many other mistakes.

I think if a therapist lets us focus on the reactions in brings up, if they work to fix what's wrong...or work to find a middle ground, and we work too...then yes, healing is still possible, even if you lose hope and even if your T stumbles to find a way forwards. I do think that a lot depends on their ability to help though. So it is reasonable to question their ability to provide help.