Sometimes, procrastination happens not because of fears, competing demands, or insufficient time. Sometimes the cause is boredom with the project. Here’s a few of the reasons a writer might become bored.
Over-plotting. Even though many writers are helped by outlines, over-plotting can take away the fun, enthusiasm, and adventure of writing a first draft. How much is too much? That depends on th person. But if this has happened to you, you might want to change one or more supporting characters, the current obstacle the POV character is facing, or add a secondary antagonist.
Over-editing. Going over your last day’s work can psych you up for a new writing session. But when you edit and re-edit, you can get bored with the material and not want to face going over the same material yet again. Try focusing on different elements of your draft, or editing the book from the last chapter to the first, or in some nonlinear order.
Cliche story. You may be bored because your story is too predictable. Check for cliched characters, scenarios, and reactions.
What all of these possibilities have in common is over-familiarity. Without an element of excitement, challenge, or creativity, writing becomes tedious. No wonder the writer finds it difficult to write!