How To Treat Sharp Pain In Stomach Radiating To Shoulder Due To Gallstone?

I have a 17mm gallstone, I have an upset stomach all the time & I get sharp pain which last a few minutes that go through my back & goes up through my shoulder blade, this has been going on for the last 5 months, my Dr thinks I should hold back from surgery as I have M.E & get very ill at times, will the gallstone get bigger?