First off, welcome! Glad to have you here! I am fairly new here too, but here is how I can help.
I did not have to do a pre-op diet. I had to provide my diet history but didn't have to do a diet before. So I can't help on that part. But the other question, you are going to have to make a concious effort to change your habits. My mom had this done a year ago and before she was totally like you. She'd just eat cuz she was bored, had nothing to do, etc etc. So she started finding things to do to occupy her time. She started knitting, riding bikes, reading books, going to friends houses. Just anything to keep her mind off of food.
LAP-BAND
® is a great tool and you can suceed if you put the work in. Good luck!!
jenn