First, quit eating at fast food places. You need to change mentality, eat lean meats (turkey, chicken, fish). Swap fruits and vegetables for high calorie items. And agree with other poster, don't drink and eat a lot at same time, just enough if you have to wash it down. Remember you can eat your way out of the surgery, you stomach is still tissue and can expand. Control the food don't let it control you.
Track your calories, that will help you know how much you are eating and will make you more alert to what you are doing to yourself.