I do get the crushing exhaustion sometimes in the last 15 minutes of therapy or right after I leave. I honestly can't do anything but sleep, I've never slept in therapy though just after.

I can relate to your reaction!! I stumbled across this concept in some book not too long ago. It blew my mind. It had not ever crossed my mind. I am one to fall asleep repeatedly during family gatherings, during turbulence on a plane, and as a passenger during frightening driving conditions - situations where I am so scared that you'd assume the raging anxiety would certainly keep me awake. But if I have no option to "rescue" myself, my next defense is to become unconscious. I even did it one night when I was upset and T unexpectedly responded to my late night message, asking me trying to call him. I emailed him that i was fine (not true) and then INSTANTLY transitioned from nyuncontrollable anxious shaking crying to 100% completely asleep. Seriously, it was about a minute and a half later. Confused the hell out of my husband.