When I’m awake I’m surely  asleep.

I sleep as if I`m in a grave.

Unaware of my day to day Activities.

My hands are tied, but I have full use of them.

My legs are chained, nonetheless I can walk

My heart beats, yet it is hard as a rock, and ice cold.

I stand here in the light, but my shadow says I am you.

I hold onto everything, however have nothing.

I am a prisoner, I do not see any walls.

Who I am?