In re-reading GTD, I'm more aware now of the times the book mentions anxiousness and uncomfortableness (or, more properly, anxiety and discomfort).
..."potential anxiousness is going to surface as you make your stuff more conscious to you than it's been."
That's the crux of my battle. Anxiety -- that gnawing feeling that makes it difficult to simply hold something, look at it and ask, "What's next?"
When it overtakes me, I try to remember to count ten breaths and do it. I hope once the positive behaviors become more habituated in my life, the anxiety will be less pronounced.