[ OT ] How to write about fear in a person 's mind ?

Fear. 
 
 It starts on the fringes of your conscious, festers there in the half-understood darkness. It's a tangled mess of wreathing blackness, frenzied convulsions of the abyss. 
 
 You, most days, stay close to the firelight of reason and logic. They cast away the unknown, push it away until fear - basic and primal - becomes somehow foreign itself, a kind of unknown unknown. 
 
 But logic and reason have their limits - the firelight only shines out so far. For some, that light grows dim and uncertain. That's when the fear approaches. 
 
 It begins like a dull throb in the base of your skull, a tingle that runs up and down your spine. Your chest constricts, your heart aches for something - is it warmth? Is it certainty? 
 
 The unknown gnaws at you, pulls apart the world you've weaved for yourself. The ugly seams of reality began to show - everything begins to fray. 
 
 The bottom is starting to fall out now. 
 
 Your breathing increases. You start to feel like maybe you should run - somewhere, anywhere. 
 
 Now it has you, inky black tendrils reach into the fading firelight, they're trying to pull you into the abyss with them. They pull tighter and tighter as you fight to get free. 
 
 As you fight to breath. 
 
 As you fight to think. 
 
 As you fight... the firelight fades away. 
 
 You're alone. 
 
 Fear.
