Melatonin and Dizzy Spells

At least once a week I experience a bout of extreme dizziness. It is accompanied by a physical feeling of being turned upside down, and everything looks upside down and blurred to me. It is very sudden and random. My body feels very heavy when this happens, like I'm on the kind of amusement park ride that pushes you backwards in your seat. My mother suggested it could be linked to the supplement melatonin. I take 5 mg of sublingual melatonin a night to help me sleep. Have you ever heard of melatonin causing this type of dizziness?