The first thing would be to check out all of your equipment of course but excluding that it my be you. Kind of like a flinch with a rifle.
You might take a day or two off off shooting then begin by shooting a 10 yards and focusing on form. Have a friend watch to see if you are flinching ( or the archers equivalent ) Just relax go through your sequence of shooting in your head and shoot.
I was at a competition a while back and I was starting poorly. There was a lovely lady shooting in the lane next to me. My sequence was stance, look at my feet, look at her butt ( which was awesome) focus on target, draw, lock, release. It worked LOL
I'm sure you will solve your problem and good luck on the hunt.