Too much sodium is just bad. If you're eating foods with lots of sodium, then you're going to retain a ton of water. In addition to drinking water, decreasing your salt intake is so important. Try to stop eating foods that are heavily processed, for a start. If you love spices, seasoning, and flavorings, look for alternatives to salt. Stop sprinkling it all over your food. A little honestly goes a long way, so try to cut back and see where it gets you.