I Have A Chronic Low Sodium Problem That Is Affected

I have a chronic low sodium problem that is affected by certain epileptic drugs. After a long period of time I can't get my sodium to stay stable.my doctor has me on 5 salt tablets a day,spaced out, 40 ozs.of gatorade, and watching juicy foods and fruits. He checks my sodium every month and sometimes weekly when it's down bad. I've been down to 120 and haven't been higher Tham 138. But mostly around 130. It's a problem we fight all the time. I have removed some drugs but my seizures had been doing so well, we hate to mess with that too much.. I've been epileptic for 40 yrs. We have no idea which drugs now are doing it or if the chronic status has became normal in my body. I am frustrated beyond words. I'm 59 and eating chips all the time is scary too. Help what is other choices to help.