I Am A High School Student And Every Time I'm

I am a high school student and every time I'm in class or around people I begin to have excessive gas. At first I thought it was just the food I was eating, like milk and cheese or that I wasn't eating enough. Then later discovered when I get really nervous I start to have excessive gas once again. It start to get really bad and It happens where ever I go. I really want to know how I could fix this problem.