Oh.... My.... Goodness....
That poor baby. Your vet seems to have NO HEART. I cant believe he told you you are over reacting. You have every right to be pissed.
My first thought was seizures as well... then i wondered if he has something wrong with his back. The seizure thing seems more correct though.
I hope and pray that your visit on Saturday is more productive and an answer is there. I will check back for updates
little Murphy