Symptoms vs Causes

Let me offer this thought. The symptoms of the struggle to write are things like:

Discovering those early morning starts aren’t working for you.
Resisting sitting down to write; resistance that shows up in the form of doing anything, but anything – cleaning the dishes, the car, the cat – just to avoid your notebook or laptop.
Getting persistent rejection letters from agents or publishers – or hearing nothing at all from them.

The causes of the struggle to write are:

Not being convinced by the fundamental premise of the book, or being clear why you want to write this book (purpose).
Disbelief in yourself as a ‘real’ writer (confidence)
Not knowing who you are writing for (reader), and not knowing what you need to write (content).

If you’re struggling with your current work in progress, what steps can you take to identify the cause?