Just tell yourself...... If it was a medical problem you'd be feeling the dizziness more often, not at select times. You've been checked out by medical professionals and have been found to be fine. You've had these dizzy spells before nothing's happened, and nothing will happen.
Personally I get the feelings at work or when out in public. Sometimes at home but not as much as when I'm in public. If I had an ear problem it wouldn't know when I'm at home/work/outside. So I tell myself its anxiety. You may also want to look at hyperventilation syndrome on Wikipedia. Sometimes when anxious people breath we take short shallow breaths which causes hyperventilation. The symptoms cause dizziness and panic.