I must not fear. Fear is the mind-killer. Fear is the little death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.
Fear is an internal force that acts against your best intentions. It cannot be killed, but it can be fought, on a daily basis. Fear wields arms such as procrastination, laziness and depression that will thrash wildly to stop you from doing what you know to be necessary, or what you truly love. Fear is out to get you; to dominate and suppress you; to break your commitments and promises.
But fear comes from within. So why is it part of us? A scum that cannot be skimmed or conquered. It is perhaps a necessary byproduct of our perception, critical thinking and decision making functions. Fear may be a basic and primal survival mechanism. Definitely, it has borne me through some difficult times (via a state of unthinking autopilot).
Surviving and living are very different. The former requires submission to fear and a miserable, hollow life. The latter requires a control of fear, and —I think— a curiosity and thirst for new experiences and challenges. Living is growing. Surviving is entropy and death.
When you feel the desperate, smothering blackness of fear all around you, recall the Bene Gesserit Litany Against Fear. Think it, say it, shout it, scream it out. Whatever it takes. Then do something about it.