There are many pressures we just have to learn to live with, but leaving something we don't want to do to fester is not one of them. Why stress yourself? As Nike might say: just do it.
GIVE THE TASK TOP PRIORITY on your 'to do' list.
TELL SOMEONE you have done this and ask them to check up on you in the next three days. Shame can be a great motivator.
SET THE BALL ROLLING, retrieve the file, ask for more information or schedule a meeting. It will give you focus.
MAKE A CONTINGENCY PLAN. Fear of 'failure' often feeds procrastination.
PLAN A REWARD for yourself. We all need carrots.