What happens when you suddenly get dizzy spells?

Last December I all of a sudden got really dizzy, there would be moments while I was at work where I would get so sick my mouth would water as if I would throw up. I blamed it on new glasses, so I switched back to my old ones but the dizzy spells didn't stop. I saw my doctor and he brushed it off and said it's just vertigo and gave me a medication to try, I have tried the pills and they do work but I just want to not be dizzy anymore, what caused this? Will it ever go away? I'm so tired of feeling like this. Please help if you know anything or have expirenced this yourself.