Heart of Darkness

I don't know why I'm having a hard time writing. I teach others how to overcome "writer's block" every semester. I've taught that concept so much that I'm sick of teaching it. But knowing a lot of tricks around WB doesn't keep its knarly fingers away from tightening around my own brain.
Maybe I don't write this thing that hangs in my brain like dead weight because if I write it, I have to face its truth. All of it. The whole horror of it. Yet, not facing it doesn't make it less true.
My brain is tired of trying to find the "good," the lesson, the positive out of the last 15 years. I wear myself out looking for parts of it to make sense, to be fair, to connect with an eternal plan. But my marriage was a betrayal--my husband betrayed the family, and I betrayed myself.
At the end of Conrad's book Heart of Darkness, the main character is dying. He looks back on his life and says "The horror; the horror."
But, so what? What does all that mean? And do I demand so much meaning from life that I cannot move on without it? Yet, the universe does not yield meaning until we look slant at it. To stamp my foot and scream, "You are foul" will not change one second of my past.