Pressure doesn't faze Sag. You have no trouble seeing a task to completion, especially if the fate of the universe hangs in the balance. Or only if the fate of the Universe hangs in the balance.
Without a hard deadline, you get sidetracked. Once a project grows too routine, you lose interest. Rather than procrastinate, try some focusing techniques.
Track big projects and actions on a calendar.
Tackle the hardest tasks first (yes, before e-mail!)
Look at and deal with each e-mail once.
Spend 20 minutes on each task (set a timer).
Forget perfect.
Take breaks.