Please don t salt your food. What happened to you is similar to adjusting the house temperature with a thermostat. Our normal body sodium us between 135 to 145 meq/dl. It is maintained at that level by a complex interplay of hormones and Add or anti diuretic hormone is the most important among them. You have an inappropriately high ADH level,that is inappropriate to your body sodium level. The normal or low sodium that u have is sensed by the body as inappropriately high and body fails to suppress the ADH release that ought to have taken place at such low sodium level. So if u take high salt body is just going to retain more water and your blood sodium level will not improve. Best practical way is to restrict water. Next best thing is to use oral/intranasal ADH analog called desmopressin. Either way since your Nephro judged it is due to trauma, it will stick with you for for the rest of your life. So adapt.