That stinks. You would think that a hospital could accomodate a diabetic diet. I would definitely call ahead & discuss this with them for next time.
Have you considered writing a letter to the hospital administration? A well written letter often gets answers/results.
I don't know about post-op wards, but on some wards here visitors can bring in food...would that be an option? I know I've brought in McDonalds on request for friends who have recently given birth, for example
I'm sure Mr. Ski would be happy to bring something appropriate in for you.
I hope you are recovering well from your surgery and your dietary misadventure, best wishes,
__________________
Julie__________________F/37/5'2"__________________Start April 15, 2009
Milestones:ozers6p4
240 - University grad weight - Met July 29, 2009
213 - 50% of the way to goal - Met October 21, 2009
Onederland - Met December 23rd, 2009 
180 - High School grad weight
163 - No longer obese______
136 - No longer overweight (yes, I know this is lower than my goal weight)
Left-Apr/09 Right-Dec/09