I can relate to that. Last time I spent serious time in a studio, the drummer couldn't get the hang of a transition that we had been working for a month beforehand and we thought he had it down. It was just adding an extra beat to the last measure of the loud section and ending up right in the soft section...after about an hour and 1/2 it ended up being a 9/8 bar instead of 5/4 (or 10/8) and we just retracked everything else accordingly out of frustration. He just kept trying to make it more difficult than it was. After the first 20 minutes I went out on the porch with a beer. It was the first time I had sat down and enjoyed the blissful escape I got from a beer. Maybe it was just the escape and not the beer.
As a side note, that was also the occation where I ended up hanging with the TSO guys!
Congrats on getting through the painful part!