Parable of forgiveness - Matthew 18

Matthew 18:21-35 is a parable of Jesus only found in the Gospel of Matthew in which there is an servant who after just being forgiven of a great debt, is unforgiving toward a servant of his own for a minor debt.  I have encountered this parable as a proof of God sending people to hell, as per the final verses in which it says, 

Then his lord summoned him and said to him, “You wicked slave! I forgave you all that debt because you pleaded with me. Should you not have had mercy on your fellow-slave, as I had mercy on you?” And in anger his lord handed him over to be tortured until he should pay his entire debt. So my heavenly Father will also do to every one of you, if you do not forgive your brother or sister from your heart.’

Perhaps this is indeed a story of God punishing those who are unforgiving.  It seems weird to me that God would not forgive but punish those who do not forgive.  Does that mean that God should be punished until God forgives the unforgiving people?

It is for these reasons that we need to remember this is a parable.  As such there is great symbolism in these stories and to quickly literalness them blinds us to potential deeper meanings.

So in an effort to help open imagination of parabolic reading, I would offer this idea. 

When I live my life and am not forgiving my neighbor, then I find that I am tormented by the grudges I am holding toward those who I am called to forgive.  

Could it be that God allows us to be handed over to the one responsible for punishing prisoners when we do not forgive not because God is punishing us, but because we are punishing ourselves?  In my life I find that I am my own worst critic and hardest on myself.  When I hold grudges and refuse forgiveness when I know I should not, I feel terrible.  I feel tormented.  

And I will continue to feel this way until my debt is paid off.  That is to say that I will be tormented by my lack of forgiving until I forgive.