Can someone please explain what is happening to me ?

Today in Health class we were learning about all those disease you may get from sexual inter courses. In the middle of the class I began to have a hard time breathing and had a headache. I asked to be excused from class to go to the washroom and the teacher told my friend to come along in case i needed any help . I got up and I couldn't even walk straight and I could see duplicates of things in the room. When I entered the washroom I could see my face in the mirror and I was all pale .. even my lips, I was all sweaty too.I could hardly support my body. I don't know what happened? This has happened to me in science class before as well. We were talking about body parts. So maybe it's just that I don't feel comfortable hearing and talking about these things. But after wards i drank some water and ate something and was excused from the whole class and I magically felt a bit better. I don't think it was because I was hungry because I ate cereal for breakfast. So I don't know. oh and i'm in middle school if that helps ? Please help me and thank youu!!