Only 9 more days....

Hi all my surgery date is coming quick and i have been having some trouble sleeping. I am so excited and ofcourse very nervous. I think that i am most scared of the thought of having constant nausea and vomiting. I have read alot of post on here and there are many people who say that they get sick like this and it freaks me out. I hate to vomit now when i have a stomache flu or bug or something. I will do all that i can do to avoid it. But i know people who have had the surgery that say when you feel like that its better to just vomit and that its not a whole lot of it. Does anyone know if it is because a person over eats or is eating the wrong things that the nausea and vomiting occur or is it just the change in your body and does it ever go away? I will see my surgeon on August 17th and i will ask him all these questions that i have but any input from people who have had the surgery will be very appreciated...Thanks