If you are having a crisis in your life, consider taking the energy and pain from the crisis and putting it on the page. Write yourself through the crisis. Perhaps the material will be publishable or perhaps it will just help you transform your pain into something a bit more tolerable. Research shows that writing about a crisis, trauma, or painful even for as little as a few days can help the healing significantly.
Another way to use the crisis: Every time you feel upset, let it serve as a cue to work on your book project. It will give you something else to focus on instead of the misery and pain you are feeling, and something positive and tangible will emerge from this difficult time.