Hey I have a hint, come here....shhhhh now listen close......
stop caring what you are hitting and practice shot execution up close to the target with your eyes closed...if you need help with a spotter to make sure you hit the target, get one. Practice exclusively on shot execution and once you masker the mechanics of the release, then and only then aim at something and practice some more....until you master the mechanics of a smooth release, you won't ever group/master the shot....
Seriously, it's no secret...you need to have the mechanics first and then and only then should you actually aim at something.....shoot hundreds of arrows with your eyes closed so you know how it's suppose to be done. Your muscles and brain will remember this, "how to" and then you can hit what your aiming at with a smooth release.