One step at a time.

"How do you eat an elephant? One bite at a time."

If you've ever ran more than a few miles, you probably understand why you need to pace yourself. Runners that sprint at the start of a race will be exhausted far before they cross the finish line. The same principle applies when trying to get work done. One solution for pacing my work that I've found incredibly effective is maintaining weekly/daily to-do lists.