Well you need to find a way to let it go because if you do not the peson the took your sons life gets to win again and that should never happen, May visit the person in jail and have it out with them or write it all down no matter what you write and burn it, By keeping it inside does nothing but causes more problems and I am sure your son would not want you to be suffering.

So sorry for your loss. The anger never goes away, you just learn to live with it.

What therapy is that and who is administering it ?