had the cold/flu symptoms for about a week and than I had a bad cough, especially at night, couldn't sleep for 3-4 days, lasted for about 2-3 weeks, no mucus, just dry cough, now is almost gone, i still cough a bit late at night. Now I been having what seems to be like a muscle pain in my back , right below the ribs, more on the side, first both sides, and now more so on the right. Plus i have been feeling a little light headed in the last couple days. Any ideas what it could be please?