There could be a few issues at root.... but the bottom line is, lead wrist breakdown and poor weight shift is the most likely.
Hit pitch shots while focusing on maintaining the angle in your right wrist, and keeping your weight a bit left..... then do the 'step through' drill (ala Player) - get your weight back to your right, through to your left (practice swings lifting your left/right foot on backswing/throughswing will help). Hit shots and take a step forward.
Never forget - Balance is key.
