Human beings have always used fear as a motivator. There are healthy ways to do this and unhealthy ones. As we are biologically wired to have a sense of fear for our survival as the easiest instant to tap, then it can be a valuable tool to help us excel when used correctly. 

Fear of failure has driven a great many people to achieving incredible things, because it inherently has the juice needed to drive focus and flow towards our goals. The advantages of narrowed focus, hormone cocktail of norepinephrine and dopamine, and accompanying jolt of energy to muscle through hard tasks is why fear is our most powerful motivator. 

The way to activate a version of before it becomes unhealthy or demoralizing is to keep the fear short-term and frame it as avoidance to a specific consequence or risk (rather than a generalized fear). In this way, it is an impulse you can work with, and manage with bursts of relaxation and mindfulness. 

Managed properly, and you have a healthy recipe for increasing resilience, learned perseverance, and better perspective of challenging tasks. Essentially you’ve then turned fear into a designed stressor that works for you, not against you.