This doesn't sound like a wasted session at all - it sounds like it has the potential to raise alot of things to explore when you are ready.

I have had these experiences with my T - they don't happen so often, but when they do it is like I am locked in a cupboard and can't get out even though somewhere the other side of the cupboard I can be aware of T's voice.

Let us know how your next session goes - Soup