A longer heavier stabilizer will help to make your bow aim better,it will stop the pin from darting around and it will tend tojust "Float" on the target.
As suggested above be sure that your draw length is not to long (better a littleshort than to long) and dont over do it on the poundage.
You may also want to get up close to the practice butt and shoot a few arrows with your eyes closed........just practice shooting with good form.......dont worry about where the arrow hits!
When you step back to shoot at your regular distance`s tell yourself its ok to aim........try to relaxe and have fun.........Iv been down that road with target panic and seen others with it.....hope this helps!!!!!!!!