I am in the same boat as you. Up until the day I got my surgery date (Thursday night) I have always drank a ton of pop. I decided that I have 2 weeks to quit due to the 2 week clear liquid diet, so I have started weening myself off.
I decided to have this surgery for a reason, and I am going to give it my full 100%. To have it and not give it my full try would be a waste. I want to be successful. That is a choice I have made.