Something I learned for self, so I am just sharing without assumptions of your therapist or your exploration through your trauma.
I found that in the beginning, I was afraid to share as if the 'person' or event that caused the trauma would retaliate, know somehow. This invisible presence or fear silenced me in my past, shamed me in my therapy and I was silenced. Afraid to speak, for the fear of not being believed, or feeling wrong instead of the sharing of being wronged- was an insufferable stumbling block. Then the pain of actually thinking upon the event... the lid shut down tight.
But as I became frustrated (as you say that you are now), I realized, I had made a deadening silent agreement to bury it all, which could not exist any longer if I was to heal. My trust issues were not really with the therapist: I had stopped trusting in me to tell my own story with expectations of recovery. That was the point, I allowed the journey to begin...one session at a time.