I must say that the pre-op diet was really hard. I was really excited when I started - like my new life is about to begin and all I have to do is stay on this easy liquid diet... right? Wrong. By day 7 I couldn't even stand to be with me, that's how grouchy I was! It's hard to do.
Post surgery is easier because you have to do it. Plus, your appetite is a little smaller from the 2+ days you go without consuming (between the day before surgery and the day of surgery). Then, when you start to see the results on the scale, it's really exciting and you want to keep going.
Hang in there, it does get better.