Maybe it would work to develop a balance between telling your story a little at a time, and managing triggers for the rest of the session. Newer research on trauma is that telling the story, especially telling it too soon, can be re-traumatizing and does more harm than good, and that a more gentle approach - visualization, teaching coping skills, EMDR, etc. can work better. It sounds like telling the story was traumatizing to you, but maybe slowing down the pace and including other treatments will be better. You always have the right and responsibility to talk to your T about how you feel and what you need.