It is the differences in culture, Asian consider good teachers have to be mean. The mean people are so critical, they will pick on your mistakes and criticize your work. On the other hands, the westerners consider good teachers should be friendly and easy to get along with, teachers and students may talk jokes to each other. The teachers point out their students' mistake but not criticize.
If you can change your attitude, considering the good teachers should be friendly and easy to get along with, then you will not nervous when you talk with your teacher.
Have you every hug your teacher? BrSwartz appears to be a friendly teacher, give him a hug then start, you woun't be nervous.