I read in Chess for Dummies that one guy snuck back in to the tournament room and cut the heads off all the queens. Another guy just gut up and walked out without saying a word once he realized it was hopeless.
I lose to the computer all the time. I am confident in the knowldege that I can still turn it off.
Martial Arts is the best teacher at losing - after getting soundly thrashed in a points sparring event, I had to turn away from the judges, straighten my uniform, get composed, walk back and re-face the judges, bow to them, bow to the flags, bow to my opponent, offer my opponent my hand in congratulations to the opponent, and then leave. The key here is that if you get out of line - there are four judges and an opponent who can kick your butt. So you learn calmness in defeat.
Later when you have had time to calmly reflect, that is when you can decide how to be hasty in your anger, and by that time you eat 5 Quarter Pounders from Mac Donalds and call in sick to work.
I think we have played some games and I sort of understand your intensity.
Actually I started playing chess to relax but at times I forget it. But we should not forget that it is just a game. That is what I remind myself..
Hope you recover fast and play with both your hands