If you manage to get yourself sunburnt then you will no doubt be in alot of pain. There isn’t a cure but there are remedies to help take away the horrible burning and soreness. Take some cotton pads and apply calamine lotion and dab onto the sunburnt areas. When it dries it turns white which is normal but hopefully it should take out the sting in the burn. You can also use aftersun to take the heat out of the sunburn but its only a temporary fix. Make sure that in future you cover yourself in sun lotion to prevent getting so badly burnt.