Sounds like shortening the draw 1/2" or so may help. If you are stretched out it is much harder to get the back muscles into the shot.

I can shoot the little goose pretty well with back tension. It becomes a matter of trust that you can hold the pin on the target and " allow' not " command" the release to go off.

Most target panic starts with the fear of missing. You have to develope confidence that your ability to hold is good enough. Don' t be scared to miss - hold on the target and allow the shot sequence to take over.