I seem to have had this choking feeling for a long time aswell, very often when singled out by an authority figure. I don't know when, but somehow I learnt/realized that the only reasonable thing is to stop having fear, because nothing could be gained from acting fearfully. It sounds a little too easy to be real, but it was a headfirst approach to the problem with no real nor perceived downsides.

Over the years, this has resulted in an interesting kind of behaviour: My mind can be completely calm in pretty much any situation. You could say that I have utter control of my mind. But interestingly my body doesn't follow! (or the subconscious). It is actually quite annoying, sometimes I downright start to shiver, I need to go to the toilet multiple times in a short period of time...all the while wondering what the hell is going on, since in my mind I'm completely fine with the situation. Last time this happened was at my final oral bachelor's exam.