Hi MyBuddyGus, welcome to the board
Sorry it's under such awful circumstance. Was it phenobarbital they had him on? There are a few differents meds for seizures, pheno is usually the first choice. I would say if the pheno didn't help, it may be something more serious than epilepsy. Does he have any other symptoms at all? How is his coordination? Does he seem to have any neck/shoulder pain or a limp? Has he had a fever? You said he came from the pound, so I'm assuming you don't have any history such as previous head trauma?
I have a baby with seizures as well. He had Meningoencephalitis, which is what started the seizures initially, but he now has scarring and a bit of brain damage, so he has them more frequently. He, however, showed no clinical signs of meningitis except the seizures, which we have been told by a couple of vets, is rare. It took a very caring (and smart) vet to test him for it. If yours only had one every 2-3 months, it wouldn't be necessary to put him on meds. But having several in a few days is bad. One thing I will say is that it's going to be expensive to find out what's wrong. The first thing I would do is a CSF tap if they continue. That would rule out (or, as in our case, confirm)Meningitis. Please let us know how he is doing and pictures are always welcome! Good luck to you both