Scottz,
Yes, Lucy is right, whiplash injuries like you had, can cause a concussion and the PCS symptoms. You need to rest, rest! I cannot stress enough how initially important this can be. Just quiet things down for a few days or weeks and see how things go. Have confidence that you will get better and stay positive. Most people respond well to rest. Your instincts on this are right. Alot of medical intervention is not that neccessary but it will be if you need documented support that rest is needed for you, to get out of work or school. Hope you heal up fast