Constant Dizziness

Hi. I have been getting dizzy very often lately, and the dizziness sometimes leads to nausea. I feel my brain rotating about 7 or 8 times a day. This mostly happens during the day when I don't have anything to eat, but even when I do, the same feeling comes and goes. The feeling lasts about 10 seconds. This began about a month ago when I got into a severe diet. But two weeks ago I decided to go back to eating healthy because the feeling was getting more frequent, nontheless, the feeling didn't go away, I still get it in the same frequency knowning the it is neither a food issue, nor a fatigue issue because I sleep about 8 hours a night.

I have also noticed that I never get this feeling when I am at home relaxing, I always get it when I am at work or at home after a long day at work.

Can you please suggest what could possibly be the problem.

Thank you very much.