Many people find that the 14th day or so the swelling peaks and then begins to subside. My guess is that yours took longer to reach peak and soon it will begin to become less swollen again. There is a gradual improvement until you're back to "normal".
It takes a full 6 months for most of the healing, and a year for the rest. What's happening is that the food and drinks are being held back at the wrap site, and it's coming back up. Back off on the foods you're eating and switch to liquid or soft, gradually introducing more aggressive foods once you've started feeling better.
Of course, whenever you have a serious concern it's time to call the surgeon and let him/her know what's going on. I can tell you, though, that many here have experienced a similar situation and it has resolved itself over time.
This is a great place to ask questions and receive support as you recover!
Nissen Fundoplication 2/09
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”