Suggest Remedy For Lightheadedness

I am a 58 yr old male, good health, 160lbs, 6'2". I had a car accident last week and the air bag deployed. I went to the hospital and after x-rays and CT scan it was determined I had a fractured sternum. I saw a thoracic specialist that gave me Vicodin and said I'd feel better in a week or so. I am now having lightheadedness to the point I need to lay down for it to go away. What type of Dr. would your recommend I see?