"That look upon her face was unmistakeable." mistakable is a difficult word to spell, I had to go look it up. There is no 'e' in the middle.
"It's the one that replays in his mind as he lie awake at night.-" Okay so the difference between 'lays' and 'lies' confuses me, but I know you should be using the singular version of the verb, so 'lie' should be replaced with 'lays' i think, or maybe 'lies'... meh
I liked your poem. Although it lacked a certain lyrical quality I usually enjoy, it concerned extremely interesting and painful emotions, and did a good job explaining them. It was both a good storytelling poem and a sort of philosophical statement about the nature of loving and hurting.