What Causes Rowlandson’s Insomnia?

What Causes Rowlandson’s Insomnia?

Rowlandson: at the end of her narrative in Journey in New Worlds by William L. Andress she reflects: “…I can remember the time when I used to sleep quietly without workings in my thoughts, whole nights together, but now it is other ways with me. When all are fast about me, and no eye open, but His whoever waketh, my thoughts are ….” What causes her insomnia?
What are the theological and psychological nuances of her reflections?