The fact that the barium swallow study showed 100% success is interesting. Did they not see some liquid taking a long time to get past the wrap? Did they have you take a solid barium food to see how that reacted? You could manage liquids fine, but have difficulty with solids due to a tight wrap.
Generally the surgeon or GI doc does dilation to stretch the wrap a bit and make it a little looser. As far as the loss of hunger goes, I suspect it's your stomach reacting from the trauma of surgery. I wouldn't be at all surprised if you have some gastritis/irritation, which would make your stomach not all that happy to receive food. I suspect when you're fully healed and no longer irritated, you will regain your hunger.
It seems you should have a long talk with your GI doctor about the problems you're dealing with. At this point in your recovery, I believe its possible for your GI doc can take over with the types of problems you're experiencing.
Don't worry. This isn't forever. Listen to your stomach and follow its lead. Try backing off on your eating and try some less challenging meals for a while. It takes more than a few days to see an improvement. It will take a few weeks at least, to notice improvement if you stop challenging your wrap and eat more conservatively.
Hang in there! It'll get better!
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.”