I often struggle with not being able to feel like I can talk. Luckily for me when I have been successful in communicating something, my T's responses have been positive. So for me the problem lies with me. The way you describe things, it seems like you have some real valid concerns. You've invested 6 months in this therapeutic relationship, if you are not getting what you want from it then it may be time to think about alternatives. Only you can know if you've given it enough of a chance.

I think all of the suggestions above are all good. Sky's idea of talking about the qualities you like best in your nutritionist sound like a good way to start the discussion about what you want from her. I think EV's comment about using this as an opportunity to practice talking to someone about what you want is great. I do think it would be a good idea to at least talk directly with her before terminating. Hard of course but beneficial.