"Fussing always ends in sin. We imagine that a little anxiety and worry are an indication of how very wise we are; it is much more an indication of how really wicked we are. Fretting springs from a determination to get our own way. Our Lord was never worried and He was never anxious, because He was not 'out' to realize his own ideas; He was out to realize God's ideas.
Have you been bolstering up that stupid soul of yours with the idea that your circumstances are too much for God? Put all 'supposing' on one side and dwell in the shadow of the Almighty. Deliberately tell God that you will not fret about that thing. All of our fret and worry is caused by calculating without God."