I know it's a no-no for a therapist to block the door, but mine did it once instinctively then realized what she was doing and stepped back. It meant a lot that it was her instinct not to let me leave in that state, even though she snapped to and realized she couldn't do that.

I do the same thing that you do, granite, which is to experience my therapist as acting like someone else/mean when I'm in a bad frame of mind. It's hard to see it any other way. That's one reason I tape record.