I am so sorry for your loss.
One thing that I find helpful with emotional "stuff" that is left over is to burn it in my burn barrel, while praying for peace and love for the other person. I ask that the hurt be taken away and that we all find peace. I figure that we cremate our loved ones bodies, and this is not really that different.
But it is hard to sort it out an figure what to keep, for sure.
But you are only one person, and you cannot be expected to to carry someone else's turtle shell on top of your own, to use your metaphor.