could be several things
ou need to see a doctor again if the med isnt working

Ask to go to a doctor who deals with the inner ear, as that is where balance comes from. My dad had severe vertigo for months and was finally diagnosed with crystals in the tubes attached to his cochlea. I'd ask about that. I don't remember what the cure ended up being but for some reason I think it involved tossing his head back and forth and to the sides really hard - something that should ONLY be done by a doctor. But, he got his head whacked around and voila! No more vertigo.