Yes, your extended period of extreme emotion and anxiety can require a week or two of settled emotions to recover from.

Your anxious reaction creates a pollution in your brain. It is similar to over-stimulation. For you it lasted for hours and now you need to find a way to stay as settled as possible to recover.

As I understand it, your head did not hit anything. It just dropped back in a whiplash like movement. Did you aggravate your neck ?