unless you are in time-limited therapy, I don't think there is much of a rush on it. Trust and being vulnerable can take quite a while (I average 4-6 months before I begin to think about trusting a T). I think the barriers will come down eventually as you feel safer with T. I've found forcing the openness actually brough me much more anxiety. I tried with my current T, and I couldn't actually speak even when I tried...
Give it time. It'll come.