How to stop myself from crying tomorrow?

Instead of thinking "how can I stop myself from crying?" you should think to your self "how can I be more ertive?" Your instructor is pushing you to become better, at least I hope so. That's what many of my supervisors and cadres do to motivate me. And believe me I've been cussed out, ridiculed and called every name in the book. But when it starts to get to you, you should really try and put yourself in a position where that person no longer intimidates or bothers you. Before your next lesson visualize how you're going to handle the situation. Don't back down and make sure you communicate with the person who is making you feel bad. Your goal is to make them feel as if "well this isn't going to make this person crack." And they will eventually stop. Go in there, be confident in yourself and if you start to mess up, who cares? Just tell yourself to do better next time and move on. If he starts giving you crap, leave or bring it up with someone else. The fact that your instructor is making you feel this way is Unacceptable. So tell them that.