Bottom line: extremely normal to not cry while talking about painful things.

I saw my last T for 2.5 years and I cried once (hardly) because a friend of mine had died. Talking about all the past abuse and CSA in my life, recounting memories of horrible things...not a tear. It wasn't fresh. I had shut myself off from that part of my life for so long I was used to not feeling anything but fear, anger, or indifference when talking about it. It wasn't that I didn't feel safe enough to cry, it wasn't that I didn't trust her, it was just that I didn't feel it within me. Perhaps this is what is happening for you.