Hi well perhaps the stones actually helped make an infection in there first and now the fever. At least the stones are coming out. A little olive oil might make it easier, also red mombin may help with spasms if it can be obtained, lemon juice and apple may help bring out any more that are in there. Cranberries might help keep the bacteria from sticking to tissues, I would not use sweet cranberry juice since bacteria like sweets. Of course every persons health choices are their own and the emergency room might be chosen if wanted. Truthfully I do not like the idea of meds for bad kidneys it makes and extra burden for them but if an antibiotic is needed... a hot half bath covering the back over the kidneys might help with infection and perhaps comfort but I would only do that to tolerance and watch the blood pressure with machine easily obtainable at a local pharmacy.
I would not use food with additives, vitamins with minerals, most meds, meat, protein, eggs, dairy, baking soda, swiss chard, spinach, rhubarb or sour dock as these may contribute to stones.