I hadthe same problemsmy huntinbuddy helped me .....Went just went over the basics..
1. RELAX !!!!!!!! take a few deep breathes to calm yourself (WE ALL GET BUCK FEVER)

2.Dont pull or jerk the bow away to look where your shot is going!( I bought lumenok this year and they helped they light up awsome)

3. Dont squeeze the bow before your shot ( try to practice w/ your hunting clothes on so you know that your bow string aint gonna hit your jacket/coat and from an elevated stand)

4.Plan your shot b4 it even happens,(When that big boy comes in where you can see him grab your bow and start thinking of when and when your gonna draw and shoot!!!!!)

hope that it helps