One of the most common problems I see in young hitters is that they tend to hit to the baseball instead of through the baseball. Your swing does not stop when you make contact. You have built up so much energy and power. Why not use every last bit of it?
Be short to the ball and long through the ball. You have kept everything nice and compact to this point. You have made contact, now extend through the baseball. Your back elbow will begin to straighten out. Allow the speed of your bat to accelerate through the point of contact with the baseball.
Your head will stay in line with your rear shoulder. Your body rotates under your steady head. When you finish, someone in the opposite batter’s box should be able to see the back of your jersey.