Cat seizures

Hi all, one of my cats has been having seizures. I noticed a month or
so ago that she was accidentally bumping into objects, and thought,
that is normal for cats, because all cats do this periodically. But
she kept getting worse, and had a full-blown seizure (very scary) so I
took her to the vet. The vet ran several tests, FIV, FIP, CBC etc.
with no conclusion. My vet admitted that he wasn't very familiar with
seizures in cats, but after observing a seizure while in his office
said that he thinks that it is epilepsy. I have been giving my cat
diazepam and she hasn't had a seizure since she started this
medication. I have been told that diaezapam is really just a generic
form of valium and can cause severe liver damage in cats. Has anyone
here had any experience with cat seizures or epilepsy in cats? I don't
want my girl to end up with liver damage from the meds but I don't
want her to die from a seizure either. I am caught between a rock and
a hard place, and I'm not sure what to do. I would be greatful for any
advice concerning seizures or otherwise. Thank you.

Hugh Jardon