Suggest Treatment For Recurrence Of Seizures After Treated Cancer

I have been taking depakoteER 500mg twice day212 rs apart. I developed seizures after Ihad pen heart augery in 999. I took Depakote then and it weemed to work well until the doctor said I did not have enough in my blood and doubled the dose. I do not remember Christmas that year (2006). For a week my family wanted me to go to the hodpital and I would not. Finally I fell down the steps l;and they took me. I was seizure free from then until I got lung cancer and an after effect after my chemo and radiation (they counld not operate because it was too close to my heart)I started passing out and getting seizures. well here I am now and I just checked the side effects on line and I have many of them.I told my doctor about some but not all because I am still getting new ones. I am only taking the medication for 2 months. My seizures are completely under control but I am extremely tired and my thought processes are evident to only me right now. I would like to know if they will get continually worse because the doctor said I will be on this medication for the rest of my life. I am now 64yrs of age and will be 65 next month. SI have quite a few more side effects but there are many.