If you'll permit me to self-promote a bit, I wrote a book out of the experience called "Eating Glass: The Inner Journey Through Failure and Renewal" to help others walk through this grief and healing season. Here is a link where I have a lot of free excerpts. [0] The chapters are broken down in topics like Burnout, Anger, Scars, Aftershocks, Health, Perspective, Courage, etc.
Here are a few lines touching on grief and the relentless drive to save a failing effort:
"Burnout is really about unrequited love. No matter how much you love your quest, it does not always love you back. Often the world does not align behind your glorious sense of purpose. Whenever some new twist or turn puts your goal further beyond reach, you must burn ever brighter to compensate. You seethe at the injustice. You choke back tears of disappointment. Despite all that, you do what you have always done, which is to hold it together through the sheer force of love. Eventually, this misalignment between your passion and circumstances opens a wound in your soul."