If you can say that you felt a slight softening of yourself in the first session, then that is already progress! The awareness of your desire to share things with your new T is very significant. If you don't feel like you can talk right away, then maybe speak with him about why it is so hard for you. It is a slow process. I have been with my T for almost three years, and we still have to spend a lot of time discussing why certain things are so difficult to talk about, rather than actually talking about those things. Good luck to you in your new therapy relationship.