I had a half of slice of pizza. I have been really good. But I feel like i slipped to the point of no return now. I do not want them to open me up and find a large liver.

Regret is a ridiculous emotion. You did it, now you have to own it. Call your surgeon's office and let them know. I'm betting that they will tell you everything will be ok, but to be sure to follow the diet recommendations strictly for the rest of the time.

A half a slice of pizza will not blow up your liver. You should not have eaten it, but really.... drink your water, do the right thing now and you will be fine. DO follow your diet after surgery. That is when the real damage can happen from bingeing, avoiding vitamins or not drinking your water. Move on with your plan and you will be fine. My liver shrink diet was only two days of liquids.