It finally went away after seeing my therapist. I was so scared, frozen in fear at first and couldn't even talk for the first few minutes. Then I managed to ask him to talk about his dogs, and that calmed me down enough to do our session and even made me smile.
I think it was pre-verbal separation anxiety which is held in my body/implicitly is what T said.
Thanks so much for helping to get me through until I saw him tonight.