I think it is pretty normal that after you opened up a bit you got scared and retreated emotionally. If we weren't scared we'd be more open normally. So I'm a bit surprised your T is surprised you retreated and got quiet. It's a process so try to be gentle with yourself. To tweak an expression I've heard to fit the context of therapy I'd say: how do you spell trust? R-I-S-K. At some point we have to start taking risks if we are ever going to learn to trust. You did and that is great. Just keep talking to your T about what is coming up for you now.