Hi mrsnacho, and welcome to PC.

Did your new therapist ask "what brings you to therapy?" or something like that? What did you say? Is her emphasis on your diet something you said you wanted help with? If it's not, you can remind her of the reasons you are coming to therapy and say that at least at first, you'd like to stick to your most pressing needs. If she doesn't listen to you and insists on pushing her own agenda, I'd say look elsewhere. (I think one of the most important qualities in a therapist is the ability to listen.)