It isn't a coincidence that the Bible speaks about "The Valley of Death" and not the "Mountain of Death." It is in the valley, where you don't see a way out, where you are surrounded by mountains, that fear comes at you. It is in the valley you are tempted to give up.
But, it is in the valley you need to remember what you saw on the mountain and hold onto it, because that is what will make you able to walk through the valley, and yet again reach the top of the mountain!