Writing's a lot like exercising, the more you do it, the easier the words roll off your fingertips. If you've had a few days off from writing, you can feel stiff and awkward. Your writing muscles are stiff. :-)
Try this free-writing exercise to loosen up.
When you free-write, it's important not to think about what you're writing. Just write the first words that come to mind, and keep writing. Don't cross out typos, don't correct your grammar, just keep writing. If no words spring to mind, you can whine on paper: "This is a stupid exercise, I don't know what to write, I …" etc.
Write "On Christmas Day, I …" and keep writing for five minutes.
Then write "On Christmas Day, he…" and keep writing for five minutes.
