I had bad gas pain for about a week it is no fun. but it is normal. Keep drinking just sip, sip, sip, you don't want to get dehydrated. Walking relieves the gas so keep moving.
You might be eating to fast. I would go back to full liquids give it a few days than mushy food. Every surgeon has different guidelines as to when to eat solids but I would listen to your body. Better to take a step back then to be in pain or have nausea.
I didn't weigh myself because I read that a lot of people gain while in the hospital. I wouldn't worry about it to much. Try to wait a week or so before you weigh again if you can.
I had a great time with my family. Everyone pitched in so I wouldn't have to cook the whole meal. I ate a few bites of Turkey, sweet potato, and stuffing. Chewed it into mush. I am 4 weeks post op.
Make sure you are getting enough fluid, dehydration can cause all sorts of stuff. I would call your surgery team or medical clinic just to be safe. When I was in the hospital my heart rate was way low they made sure my head was up in a sitting position and lots of fluid.