Yes ,this lightheadedness is due to your neck problems ,but most come from C2/C3,so perhaps you need see doc again.
Have you examined the possibilty of a vitamin deficiency like iron? You may be anemic. Of couse, I am not a doctor, but I have experienced this feeling and it was due to my diet habits. I was one to never eat breakfast which would cause my sugar to plummet and then become very weak, lightheaded and sick feeling. Just a suggestion to look into.