There isn't much you can do, need surgery as you’ve mentioned. Once your gallbladder has done battle with the stone, the walls can become inflammed and sore. Limiting yourself to fewer meals may help. The gallbladder contracts to expell the stored bile everytime you have a meal. Of course you can't starve either, so the tradeoff problem presents itself.
Forgot to add in main post: I have 1 stone and it's approx 1.5cm.