I had something similar too a few times. I'd wake in the night and if I turned onto my right side an amazing headfull of dizzy hit me hard..I felt ill. I turned over to my left side and it was mostly gone and it would last for a week on and off. Usually it was before the dot so when and if I get lightheaded now during that week before it usually means a migraine is coming.
However this was different and I remember asking Dr. about it..cause it was not around the dot time and she said it was a virus going around and there was not much I could do about it. When it went it went for a long time and did not come back for at least a year - with me anyhow.