I don’t quote it much here but Frank Herbert’s Dune series is probably one of the most frequent things to pop into my head (Laura Ingalls Wilder is up there, too).
Blame it on early exposure and complete world building, I guess–but the Litany Against Fear has served me well for many years. Here it is:
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.