I had a friend that everyone disliked him because of they way he looked. Nothing he could change. It could be you're just over thinking it. I would make sure you do basic hygiene before each class (shower, change, shave, teeth, brushed, deodorant, hair done). If you have acne see a dr. as it can be preserved as dirty, carry and chew mints/gum. Honestly that's all you can do.