Masturbate until your arm falls off then beat yourself to death with the other one and a rock. Face it. There's no way you're getting out of whereever the hell this place is. You might as well enjoy yourself then die.
After the third ejaculation, your interest in masturbating has faded to nil.
Rip a small section off of your shirt and make a splint for your foot.
Walk to the left and grab the dropped rock, put it away, and feel around the metallic object.
You successfully craft a splint by tearing your shirt apart and wrapping it tightly around your foot together with an oddly shaped rock. You are not in the shape to run, but at least you can walk again. You stumble into the darkness, and walk in the direction of the metallic sound. You can't seem to find the rock you threw, but you've discovered what it had hit. At floor level, there is a large ventilation duct in the wall exhausting warm air.
You try to remove the grating, but it is a waste of effort. Even the rocks crumble when you try to break it open.
EDIT:
It is pitch black. You are likely to be eaten by a grue.
