That sounds like vertigo. It may be related to the car accident, but it's an inner-ear problem. My mom has vertigo, and if she tilted her head or moved her eyes, she'd get dizzy. Standing on a chair was enough to cause it. I sometimes get it about once or twice a month, but I usually thwart it by splashing cold water on my face. Try that and see if it helps. I think there's also ear drops that can help it.