Hi I'm on day 2 of my preop diet too. I only have two weeks to do before surgery and it sounds like my diet is a bit different. I'm on Medifast and I have the option of 4-5 servings of any combination of shakes, bars, and soup. I'm also allowed to have lean protein and 3 servings of non starch vegetables in the evening for dinner.
I feel bad now for complaining about the diet compared to what you have to go through. Good luck and I know you can do it!