Yeah I can relate, in situations like this though I was recently thinking would role play help, try to flip the flight response of anxiety into the fight response cause its 2 sides of the same coin anyway, but fight is more useful than flight in these type of things.
For instance Imagine you're an english spy in front of a group of Nazi soldiers & you can't let them suspect you or something.
And all our yesterdays have lighted fools the way to dusty death
Out, out, brief candle! Life's but a walking shadow,
A poor player that strut's and fret's his hour upon the stage and is heard no more,
It is a tale told by an idiot, full of sound and fury, signifying nothing. - Macbeth