Collection of day 2 & 3 after coming home from the neurologist. They don't know what I'd causing them.hes now growling and hissing and spinning to the right. Still having the seizures.

Kitty was a very social non aggressive friendly cat until 6 days ago. He suddenly started having focal seizures with lip smacking and chewing. They found a small tumor under his tongue and removed it 5 days ago, and then was brought him. The seizures got more frequent and was taken to a neurologist and kept for tests and to figure out what medication would help. They said he was seizure free for 24 hours and sent him home 2 days ago. Yesterday he was having the lip smacking focal seizures and acting unaware of things and who we were. As of 9 this morning, half hour after hid phenobarbital dose, he has started growling and hissing. He's never done that before. He acts like he doesn't know us now, and isn't interested in food, water, and hasn't used his litter box. We are worried as bout his quality of life. Is this going to stop? Is if going to get worse? Our hearts are breaking. We are hoping he gets used to the medicine. The tumor was not malignant that was removed, and now they think he may need an MRI for more diagnosis. $5000 on kitty in a week. I don't know if we can spend anymore not knowing if there's a good result at the end of this. Has anyone been through this???