Truisms:
"I must continue to choose between the lesser of two evils."
If you increased your courage (for any reason), you could overcome your fear and choose good instead.
"I'd rather have the evil that I know than the evil that I don't!"
It seems you would rather have the evil that you know over the good that you don't too! Your fear of the unknown is enabling the evil that you know.
"A bird in the hand is worth two in the bush."
Are you sure it's a bird you're holding? Would the equation change if there were a million in the bush? How about if it was two in Bush?