Take another look at the 2 step drill and work on getting the hips moving forward as the hands go back. The back foot hits the gas first just after the body begins the forward lean and the drive foot hits it just after that. Here are few gems from the DM thread:
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-5.html#post229947
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-8.html#post240500
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-9.html
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-10.html#post240869
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-15.html#post280717
Loosen up that lower arm and allow it to lag/hang from the elbow as it comes over the top. Pull the ball/lower arm around the circle and into whip.
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-5.html#post229947
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-8.html#post240500
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-9.html
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-10.html#post240869
http://www.discussfastpitch.com/softball-pitching/18135-drive-mechanics-15.html#post280717
Loosen up that lower arm and allow it to lag/hang from the elbow as it comes over the top. Pull the ball/lower arm around the circle and into whip.