Tremolo,
Have you taken a deer before? Relax don't put too much pressure on yourself. Just focus on an aiming point stay down and make a good release and follow through. Don't jerk to look at the arrow flight. I would imagine that is what is happening. Make your routine the same target vs game. The only additional comment i would make is make sure you practice in the same clothes that you hunt in..upto and including mask and gloves.