Fear and frustrations are useful things. When you're in a swirl of frustation because you can't see the way out or you hate your life, that energy fires up the cylinders. It's like cranking the motor that drives.
Fear of failure is the best motivator there is. At least until you're enlighten enough to be completely fearless, which is the ultimate goal for all of us, right?
Appreciate how fears of failure and of wasted opportunity can drive a person forward.