I woke up one day very dizzy and it lasted about two hours what is the cause?

Dizzy. First step is visit to your pcp to check your vital signs, review your medications, do exam & order blood work.
One way to know. . Only way to know is to do a workup and physical exam. It could be low blood pressure or cardiac in nature. Tit could also be the endolymph in your ear which coordinates balance. There are different things it could be. If it continues then see a physician.