Good luck for surgery hon, hope it all goes well.
One thing I would say though is that you should probably come off the diet. I know you want to stay on plan but it's actually really important to have more calories for healing. By keeping your calories to a vlcd level you could prolong recovery dramatically. I know that on S&S you have to be out of ketosis to have a general anaesthetic and can't go back on plan for several weeks after surgery. The last thing you want to do is take longer to recover than necessary.