Thank you for the query.
This sounds like whiplash indeed. And the pain you are experiencing is most likely caused by pulled muscles and tendons. However neck stiffness
is also a symptom of increased intracranial pressure. Lightheadeadness can be also a symptom of such increased pressure. Other symptoms you may also notice are nausea, vomiting, blurred vision
I suggest you to visit your doctor (neurologist
would be the best choice) and have at least physical examination to make sure nothing serious has been injured.
Hope this will help.