Clarity is lost through the lack of decisions. Such that in making those decisions, one is afforded a clarity and the security of self that goes along with it. When seated in sadness, that is a decision made in the lack of decisions toward a vision or toward the next step as such. To solve such crises of faith, philosophy, and action, simply write out that which you wish to have or which you would rather be left for others to experience. Through this process of elimination, one finds that which they do want and hence construct a vision in line with their guiding principles. Each action thus on the grander scale is toward that vision, and each bit of effort and grind serves a purpose, and under a purpose that is aligned, one can conquer and persist through all things.
Meditate.