Well, taken at face value your therapist said she doesn't 'believe' in labels and diagnosis. So that's it. Personally, I would also want some sort of diagnosis too though, so as to understand and to find ways to manage my group of symptoms better too. My hunch is that some of them don't believe in diagnosis because they don't think it would help. But they forget that it's you who is struggling with your mental health, and not them. Very lackadaisical approach on their part.