Hi,
Thank you for posting your query.
Based on your symptoms, the most likely diagnosis in your case is 
peripheral vertigo, a vertigo sully not related to brain-related causes such as 
brain tumor or infection or 
ischemia (lack of blood flow to brain). Normal 
MRI confirms that your brain is normal.
In your case, the most likely cause could be benign paroxysmal positional vertigo, where symptoms usually resolve in a week or two.
Please continue 
vertin as advised and you should improve soon. 
I hope it helps. Please get back if you require any additional information.
Wishing you good health,
Dr Sudhir Kumar MD (Internal Medicine), DM (Neurology)
Senior Consultant Neurologist
Apollo Hospitals, Hyderabad, India
Click on this link to ask me a DIRECT QUERY: http://bit.ly/Dr-Sudhir-kumar
My BLOG: http://bestneurodoctor.blogspot.in