Here's Anne Lamott on why we read and write from "Bird by Bird: Some Instructions on Writing and Life."
Writing and reading decrease our sense of isolation. They deepen and widen and expand our sense of life: they feed the soul. When writers make us shake our heads with the exactness of their prose and their truths, and even make us laugh about ourselves or life, our buoyancy is restored. We are given a shot at dancing with, or at least clapping along with, the absurdity of life, instead of being squashed by it over and over again. It's like singing on a boat during a terrible storm at sea. You can't stop the raging storm, but singing can change the hearts and spirits of the people who are together on that ship.
And Steven Pressfield discusses Resistance in "The War of Art: Break Through the Blocks and Win Your Inner Creative Battles."
Are you paralyzed with fear? That's a good sign. Fear is good. Like self-doubt, fear is an indicator. Fear tells us what we have to do. Remember our rule of thumb: The more scared we are of a work or calling, the more sure we can be that we have to do it.
Resistance is experienced as fear; the degree of fear equates the strength of Resistance. Therefore, the more fear we feel about a specific enterprise, the more certain we can be that that enterprise is important to us and to the growth of our soul.
Related: Woody Allen describes his writing process and how he wrote 50 jokes a day...while on the subway