Using metaphorically is quite a task and the way you used it, is well done. The thoughts were outstanding at the beginning. My first instinct was to say they person is suffering from depression and it could be a self motivation poem. But its deeper than that. You are trying to fight your sadness or your negative emotions for your child. That tells me even through the sadness there is a little bit of hope inside. The shovel is a great part because of the way you used it. You think you are digging your own grave but you just want to bury the memories that haunt you. Then that spark of hope comes in... The child. Someone you seem to live for. Even if it just for a short time... I believe any happiness is good happiness. Well written!