Eat, drink, inhale. Exhale, pee, and defecate. You become the decisive sustainer of the ecosystem.
Remember this when you feel overwhelmed. Whenever you feel inefficacious, recall it. The whole cycle of life persists even after the body dies, through decomposition.
You are the bread of life, the water of life; or, to use austere words, you are the urine and the feces.