Hi! I am almost at my 3 year mark after weight loss surgery, and 120#s lighter!! Anyway, I still don't eat as much as a "regular" person, and when my husband and I go out to eat around our town, I always take a doggie bag.
That being said, we go to Disney World 2-3 times a year, and I think you just have to chalk it up to money spent. You can choose not to go out to eat, or eat counter service meals and share, or you can suck it up and spend the money. I am not trying to sound harsh, I just go with the state of mind that I am on vacation, and its for my whole family.
If you are not doing the dining plan, you can go to regular restaurants and share a meal with someone else. Buffet and family style meals are different, but I take a little bit of each and enjoy myself. For me I guess that I look at it more as a time to relax with and enjoy my family while we are on vacation, and I can enjoy myself so much more now that I am healthy!!
Good luck with your surgery, I really hope that it all goes well for you, and that you have a great time on your vacation!