One of my favorite scenes from the movie The Replacements is when the Quarterback Shane Falco, played by Keanu Reeves, during a team meeting speaks of his greatest fear. "You're playing and you think everything is going fine. Then one thing goes wrong. And then another. And another. You try to fight back, but the harder you fight, the deeper you sink. Until you can't move... you can't breathe... because you're in over your head. Like quicksand."
In my business I see a variety of companies and all sorts of office situations. I find that far too many employees have a tough time speaking up
when they are in over their head with tasks given them; whether it's they can't
handle the extra work or in some instances they're not as qualified as
they said they were. Speak up, don't wait until you're in "quicksand" and
have no way out. Not only are you hurting yourself and damaging your business
reputation; you're potentially costing your company a lot of money, as they
will need to bring in qualified people to correct your errors and to get caught
up with the work you were not able to do.
Bottom line: It is better to fess up
and admit you're in over your head and need help than to cost yourself a job.