Persistent Headache, Lightheadedness & Nausea: What Could It Be?

Question
Hi, I am a 26 year old woman and I have had some problems lately.  One month ago I had a headache that lasted a couple of days, and I took over the counter meds for it.  I felt fine for about a week then it came back this time I felt lightheaded also, then came the nausea, just didn't feel like myself because I've had a clean record until now.  It got so bad that I went to the Med Express and they told me that I had a virus, but it wasn't the flu which is what I thought it was.  So they just told me to go home and go to bed.  A couple days later I still had the symptoms and just didn't feel right.  So I went to the ER and they gave me an IV and took blood, they also did a scan of my head because of the headaches.  They said everything came back negative, and said it was probably tension headaches, and gave me some meds. I felt better when I got home, but a couple days later I got this pretty bad cough that lasted about 5 days.  Now that my headache is gone and my cough is gone I still feel nauseated.  Please help me!  I'm afraid something is really wrong with me. I just want to feel better for the holidays. Thank-you so much. God Bless!

Answer
if they did the screening labs, you are probably OK... I would suspect you may have a lingering low grade sinus infection.  I would get established with a primary doc  so things don't have to be repeated as the eval progresses, but I don't see this as symptoms of something "real bad."