I appreciate this thread greatly. I'm on my second day of student teaching right now and my brain is absolutely fried. All the concentration, fatigue, constant socializing with extroverts, getting up early, etc. is taking a serious toll on my mental reserves. So far, I've only had to observe and do simple tasks (check homework, stand in front of the class while being introduced, etc.) but those little things have still taken courage, especially when I feel the anxiety escalating.
I'm really concerned about next week when I will actually begin to teach lessons, so I called my old psychiatrist and he called in a prescription of Inderal (a beta blocker) to help with the shakes, heart pounding, etc. Also, I have some old leftover Klonopin from years past, so I'll probably take a little of that during my first few days leading the class. My hope is that, after a few days of real teaching, I'll get comfortable enough with the routine to stop taking the meds and that my confidence will build from there.
I know I will love teaching (and be good at it) if I can get past all these stupid anxiety symptoms. Your words of encouragement are inspiring me to keep at it!