Jules is right, you've started your pre-op way too early and setting yourself up for failure...you only need to do it for a week to 10 days before.
I had the wrap done with Dr Hruby in August. You won't feel much if any pain after as you will be given regular painkillers, but because the stomach is wrapped in on itself and the inside walls are touching to start with you will suffer nausea for the first 24-48 hrs, for me that was the worst part as I hate feeling or being sick! Like childbirth though once you see the weight dropping of any memories of the op fade away because you realise it was all worth it and the best decision you ever made!
It's good you have your sister going through it with you. Don't forget your google translate app lol
There's lots of threads on here about ops with Dr Hruby, with lots of info if you search around.