feeling weak diagnosed with gallstones

hi i have been diagnosed with gallstones and waiting for a operation in march but recently for a few days now ive been feeling very week my left arm has been feeling ever so weak like ive got no strength in it sometimes i have to clutch on to my left arm with my right to make it feel better ive also been getting headaces as well as feeling weak in my body could it be something to do with my gallstones thanks[/b]