Okay, first of all there are hormones that were released during your surgery, so you're probably a little emotional right now.
Second, did you think you were going to eat double cheeseburgers for the rest of your life? That part of your life is over. That's why you made the decision to get healthy and have the surgery in the first place.
Third, the nausea should be over by now. If it isn't call your doctor and check to see why you're still nauseous. Maybe they can give you some anti-nausea medicine. Is it only when you eat? Is it all the time?
Finally, talk to the therapist at your surgeon's office or through your health insurance. The mental part of obesity and hunger is the hardest part to tackle. Let somebody help you through it.