I had my band done the same day. I felt the same way. I wondered if I was doing the right thing, too. Anyway, I hope that someone replied to you sooner and that you're doing better. The rash sounds like an allergic reaction. Now that it's 7 days post-op, how are you?
Aside from the pain, my brain was still on overdrive and craving everything. It's not easy to turn those thoughts off. I imagined not being hungry immediately post surgery. It took a couple of days to convince my brain - it was frustrating!
Take care,
Lisa