17 lbs is amazing! Don't panick about your little cheats. You can jump right back on track. The pre-op diet is mainly for the purpose of shrinking your liver durging surgery to decrease bleeding and after a 17 lbs weight loss I'm sure you should be fine. I had my surgery just a little over a month ago and trust me, The night before the big op day..I broke down, and had anxiety, and cried. But the next day..I was up and ready to go. The surgery was such a cake walk. Easier than the pre-op diet. It went so smoothly and I have never ever regretted it. I think you are doing a great thing for you and your health and of course it's natural to be nervous but once it's done and over with you will be saying "Oh was that all?"