How to stop Ging at school?

I am Lactose Intolerant, and I want to stop farting even though I do not eat Dairy products anymore ever since I found out that I was allergic. At school I feel normal but 2 periods later my brain doesn't tell me that I will gas 3 times every 5 seconds!This always happens during school and I cannot understand why? I can feel gas building up and it releases on it's own. And I smell very disgusting because the smell stays on me from everytime I gas! My teachers p around me and can smell the odor, I cant take it anymore, I just want a list of things I can do, and eat so this can STOP! Please help!!