I was sleeved in July of 2013. My son was also 2 and a half. He is still nursing! I kept a full bottle of water with me at all times. My doctor told me to remember we have people who don't have running water in other countries who do okay. As long as you are getting something and don't have major complications you should be fine. You will lose a bit of your supply the first few days. But the more you heal the more you can drink and your supply will eventually get to what is needed, as long as your child is still trying to nurse.