I had a similar problem. Still do from time to time.
When I first started teaching Teakwondo it was a bit shaky. I was a little nervous, but as long as I had a game-plan I knew I'd be o.k.. The thing that would really trip me up was not knowing what I was going to do next. It was similar to a cascade chain reaction, where I would realize I didn't know what I was about to do, which made me nervous, and then I would realize that I'd been standing there thinking and looking uneasy in front of the class, ect. Bad line of thought
. After that happened, the idea haunted me for quite some time.
I completely agree with JinnKai. Messing up, or not knowing how to do something, won't make people think you are inept. Its completely normal. We just tend to blow it out of proportion a little in our own minds. We are normally our own harshest critic.
Glad you're doing better