I think the doctor hit the nail right on the head! I've noticed that even when I drink decaf tea, soda, and coffee the same thing happens to me. And wasn't until I told my doctor that she brought up the same point. There is still a small trace of caffeine in the decaf stuff, too. Even chocolate! Good luck, I hope you feel better soon!
Sorry I forgot add it:
(AKATHISIA - A BRIEF REVIEW
D E Nelson
The Orchard Clinic
Royal Edinburgh Hospital
Morningside Terrace
Edinburgh)
http://www.smj.org.uk/1001/aka1001.htm
There is some caffeine even in decaf coffee and you may be very sensitive to this small amount. Experiment, stop decaf or any coffee and see what happens.