Winter blows ice into my lungs, I cannot run away.
But my breathe warms the air, I make mist and let snow fall. I affect this earth as much as it affects me; I am a piece of this grand puzzle, sure, without me you could probably still see the big picture, but it would not be complete.
Exercise is without a doubt one of the most powerful antidepressants I know of, its all natural as well. No doctor needs to prescribe it. Just put some shoes on, they don't need to be fancy, and start running. Outdoors is better than in, but it will do the trick. Don't like running then swim, cycle, skip rope, box, squash, tennis. Any form of cardio will do even a gentle walk.