I'm not a director but I know what fear looks like..most people when they are scared to death are indeed feeling helpless, they throw up there arms in an instinctive pleading posture to the threat ,when adrenaline gives a full dump the knees buckle, the eyes and face give a pleading for mercy look unless they turn it into aggression then rage comes full throttle, also when real fear hits there is a freeze, anyone ever have a gun pulled on em or been threatened then theres an instant freeze if you dont know how to control fear, I'm not sure how you would show that to a viewer but i could think of some ideas..go to geoffthompson.com and read an excerpt from his book red mist..he's a martial artist and he knows fear, they way he describes it is dead on and a good guideline on how to maybe show it..just my two cents..
Rob