Never mind setting me back, I was completely hysterical for days afterwards. Crying, shaking, terrified. Had 3? maybe 4 sessions 18 months ago to address single issue from 2002. Certainly broke through emotional barriers and I was prepared for "no pain no gain" but not the all consuming fear it invoked.
I had to stop, I felt as bad as I had iniially. That was probably the point but I still couldn't process it.