Poor baby. I would definitely look for a new vet. This could be anything from an ear infection (yes, they do get them and that vet needs to go back to vet school imho) to
a neurological issue. I personally would do what Gemy suggested...head to a board certified internist for starters. Might be a few dollars more, but they often are quicker to get to the diagnosis. You can find one at:
American College of Veterinary Internal Medicine > Home
We have a member who lives in Vegas...I will message her to see if she can make a suggestion about a vet.
Good luck, welcome to YT and please keep us posted!!