I Am Having Break Through Seizures On Three Medications Phenyton

I am having break through seizures on three medications phenyton ex 400mg in the am and300mg in the pm' gabapentin 300mg tid and 1500mg @hs Diazepam 10mg tid. This is termed intractable seizures.I had been stable for 5 years .Seizures just start ed reoccuring isthere hope that a med change will get themunder control again .Ialso have multiple other medical probles heart disease etc my pacemaker will need changed within the next year. If the seizures cant be controled idont want any futher life sustaing thing done Iam60 years old and Icant accept this situation . iam not sucideal Iam just wanting pallative If this situation can not be fixed if icant drive and live an independant life.