What Causes Persistent Dizziness With Feet Wobbling?

hi there i have been suffering with bad dizzy spells for about 4 months and they are getting worse by the day they now last for anything from half an hour to well over 2 hours, when it happens i cant function properly i get wobbly on my feet and rock from side to side as if i am drunk when i sit down its just as bad it doesnt go away even if i eat i feel daft asking my doctor about it as he will just prob give me a blood test and send me on my way, i dont get headaches with them i am just getting worried cause they seem to be more frequent now and lasting a lot longer, i even have them when i am asleep they will wake me up