Psalm 3 and Procrastination

I've put off writing about Psalm 3 for a few days.  I started Psalm 3 back on February 1, finally finishing on February 14 even though I was reading consistently.  If that seems a little crazy, let me explain.  When I read through Psalm 3 the first time, I realized I didn't know or remember enough about David's life to understand the depth of what he wrote in the Psalm.  Before you even get to the Psalm itself, there's a note saying that David wrote it when he fled from his son Absalom.  I couldn't remember the specifics of how that came about, so I decided to reread 1 Samuel and 2 Samuel to get some background.

I'm not sure how in-depth I want to go into the history that I read about as I write the blog.  I took fairly detailed notes when I read through Samuel the first time, but my whole purpose with the blog isn't to be intellectual, but highly personal and honest, focusing on my relationship with God.

Just based on a quick preliminary look at the outline of 1 Samuel and 2 Samuel that is in my Bible, it's easy to tell that David did not live an easy life.  He was alienated, hunted, pursued, and attacked.  He also committed adultery and murder.  How can a man that went through that much still have the strength and faith to say:

But you, LORD, are a shield around me,
   my glory, the One who lifts my head high.
I call out to the LORD,
   and he answers me from his holy mountain.

I lie down and sleep;
   I wake again, because the LORD sustains me.
I will not fear though tens of thousands
   assail me on every side. (Psalm 3:3-6)

In light of that, how can I possibly be struggling with my faith as much as I am?