Something very similar happened to me in my last session. It wasn't the first time I dissociated in session, but definitely the worst episode so far -- and the first time t really noticed and tried to bring me back. He asked me to sit up repeatedly and after what felt like ages I managed to shift a little in my seat and started coming back. He then just talked about everyday stuff, which was helpful.

Touching my hand or shoulder would probably have brought me back, but I'm not sure I could have dealt with someone touching me. So I'm glad t didn't.