A Geek with Writer's Block!

Ah, at last the house is empty and quiet. Anne's at work, the kids are at summer school, the dogs are working really hard (also known as sleeping on the kitchen floor) and I have the entire place to myself.
It should be an easy and productive time to sit down and get some of these stories out of my head, but whenever I start, I feel almost ADD-stricken and immediately lose interest and motivation. It's been like this for weeks, and I've finally had enough. I vowed to figure out what exactly was giving me writer's block, so I could destroy it and move on down the road before it had a chance to rebuild itself.
I started out with what I figured would be the first chapter of the son of Spongebob Vega$pants, the still-untitled saga of CruiseTrek 2006, with book signings in Montreal and Boston.
I stood in a small empty room, one story above the street, and looked out the window. I clutched my well-worn copy of Just A Geek in my hands, and tried to ignore their slight trembling.

I've done this a hundred times before. Why am I so anxious today? A woman walking a dog caught my eye, and I followed them down the block and across the street. There was a knock at the door behind me.

It was Scarlett, the manager of the bookstore.

"Are you ready for me to introduce you?" I could hear the buzz of people in the room behind me. It was hot and humid, and though one fan was working very hard, it wasn't enough to keep the stuffiness entirely at bay.

I took a deep breath. "Yeah," I said."
The Internal Critic peeked over my shoulder.
"That pretty much sucks," he said.
"You've been saying that about everything I write for months!" I said.
"Why don't you take a break?" He said.