To be honest, I'm a little tired out from a strenuous day at work so, going to read this a bit better tomorrow and address.
On a brief first skim: you are talking about how at work/school/meetings you don't worry about the outcome most of the time (grade/employment, etc...) but rather worried about the fact that your mind would go blank.
It's actually the opposite
My main issue wasn't my mind going blank ... I was sort of lucky that I could push through that and the other fear symptoms. What I worried about was the effects on not performing well on school grade or employment. It's the "What if ..." type thinking/worrying.
Actually, that was one of the easier issues to deal with because for me it was mainly a thought with a slight fear (compared to the actual events). By practicing "I'll do the best I can do" and various interrupting techniques, I was able to deal with that aspect after a while. But the rest of the fear response still remained, until I looked for other ways to deal with it and eventually something worked.