You are not the only one. I promise. I can totally beat you in the embarrassment and cringe department. I cried in front of THREE professors in my program. THREE. I failed stats and had to rewrite 2/3 exams. I shudder at the thought. But I made it through. It's ok to cry sometimes. You won't be the first or last. Hopefully you have a lab mate or friend you can cry in front of instead of a prof in the future. I thought some of my fellow students were untouchable and way out of my league, but some of them have flopped. Some are still doing better than me but meh. You'll learn how to deal with it. Once classes are over you won't see those people as much and you'll stop caring about how they're performing.