Getting full after tiny amounts of food is totally normal. The top of your stomach, where the message of fullness originates, is swollen and stiff. Because of that, the brain interprets "fullness", hence the early satiety. This feeling of fullness gradually subsides as healing progresses and swelling subsides. Until then, many tiny meals are best.
As far as eating goes...there are still surgeons who expect their patients to remain on a liquid diet during the period of peak swelling. That way, there are fewer problems for them to deal with. Sometimes swelling is severe enough to require that. Rather than providing their patients to use their own judgment regarding what they can and can't manage, they make the decision for them. Liquids. And indeed, liquids do their job. They can be swallowed even during peak swelling periods.
There is another philosophy (which was the one held by my surgeon), which is to let the patient use his/her own judgment about what they can eat, with the caveat that only things that can be "chewed to a liquid" be eaten, and that patients should stay away from hard meats like steak, as well as untoasted breads.
Starting on Day 6, my surgeon released me to eat "anything that can be chewed to a liquid", which I did without a problem. Of course, during peak swelling, I stuck with very soft foods/soups. I just listened to my body, and only swallowed things that chewed to a nothing/liquid/creamy consistency. It was trial and error, and I found multitudes of delicious treats that could be chewed by my perfectly capable teeth, rather than placed in a blender to do the same job. In my opinion, chewing is the best part of eating, and why let the blender have all the fun!
Even bread, when well toasted, chews to a liquid. Saltines do the same. Actually, I found crispy things (no raw veggies!!) chewed to a liquid just fine. Just keep a paper napkin handy, just in case you find yourself with some food in your mouth that doesn't chew properly. You can deposit it discreetly in the napkin and nobody will be any the wiser!
My surgeon said that "even a bolus of mashed potato can get stuck". It's more a case of not swallowing anything that doesn't chew to a complete liquid. That means ANYTHING. Take very small bites and chew, chew, chew, chew.
I'm sure sleeping on your stomach at such an early stage of recovery isn't the most comfortable thing, and I'm sure it can cause some pain. At Day 4, all those things you describe can and will cause pain. This too, will pass. Healing takes time, and you're in the thick of the roughest part of recovery. Hang in there! It gets 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.”