I Get Really Lightheaded At School Or In Public Places.

I get really lightheaded at school or in public places. I am a teen girl. It has been happening for over a month. It started one day when I had a fever and a stuffy nose. My light headedness worsens when it is very loud or bright lights. My blood is fine I had it tested. Also I am a very social person so I don't think it is anxiety. Please help.