Perseverance. What makes you stay with a thing that is challenging? There is an internal nudging to do your best, to see it through to the end. This is part of the evolutionary drive of the soul, but it is more than survival instinct, dear one. There is one primal instinct that goes beyond survival, and that is to express love. You do this by shining your light. Persevere when things seem dark as they will in a world of duality. The sun always comes out again.
You are so very loved.