Shepherd the flock of God which is among you, exercising the oversight, not under compulsion, but voluntarily, not for dishonest gain, but willingly;
Two different Greek words. The first one should be translated perhaps anxiety. Casting all your anxieties upon Him. The second Greek word is used as of a shepherd watching over his flock. For he is watching over you with concern, loving concern. So "casting all of your anxieties on him; because he watches over you with loving concern."