Vertigo, Acidity, Nausea, Diarrhea.

Almost 2 years back, I felt sudden severe dizziness. I thought it might be due to tiredness but It lasted continuously for almost five days however it gradually decreased over time. Since then very frequently(twice/month) I was suffering from this condition.Some common symptoms that occurs along with dizziness are indigestion, gastritis, nausea & diarrhea. Rare symptoms include severe neck pain and headache. I consulted a doctor and he told it might be due to problem in my ear. But after few tests, It was normal. I have been prescribed to take Vertin and Pyrigesic for vertigo and headache. However, Fortunately for the past two months I was fine. But it started again last week. After 4 days, I feel better now but haven't recovered completely. Whenever this occurs, I couldn't get up from bed. I can only lie on my left I couldn't lie straight or on my right. This condition is affecting my lifestyle very badly. The underlying cause is still not found. Please suggest on what to do further.