Yeah, the problem seems to be as follows:
You've associated learning with being wrong/laughed at - anxiety.
You're anxious about knowing and presenting your knowledge and judgement.
What you have to do is understand that what happened in the past and what could happen in the future are all in your head. Basically, they don't exist.
With that in mind, approach learning as an intimate process, don't try to think what your teachers would do/say in your situation, or try to guess what they want from you. It's not about them, it's just you, your brain, your mind and the knowledge. And later, it'll be you and the exam paper. That's why it's important to understand and process the information in your way so that you can retrieve it.
Then test yourself to see that what you know is perfectly valid. Answer yourself why that's valid and convince yourself that what you know is right by understanding it in its full context. If someone asks you something that you can't really answer, think about it: it's not because of you, it could be because of them, maybe they don't know what they're talking about. If you really didn't know something, then there's no need to worry because no one knows everything and the best you can do is progress and improve yourself.