Hey Pink,
It sounds like you have already begun the discussion of how to manage the feelings that come up when you are still in his office. It must feel impossible to not respond in the way you are accustomed. You know what though? Again, I notice your courage in telling him exactly where you were.
Do you think it's possible that SI is a component of the "fight, flight or freeze" response to trauma? For example, SI could be part of the fight response.
I know that for me, as a child I engaged all three responses depending on the circumstance. In some ways I think that when I SI now, it might represent an attempt for me to break out of the freeze response; a way to feel or engage.
((((((((((Pinksoil))))))))))
Peace