I think I know what you're getting at.  I would suggest pausing at the top of your backswing as you practice.  This should make you less anxious on the transition to your downswing.

I would say to really watch your tempo and your desire to "crush" it off the tee.  Just use your normal swing, don't try to kill it.  I would also make sure that you are thinking "target" and about the shape of your shot, and not about your swing.  Pick a specific target and concentrate on making a smooth swing to get it there.  That will get your mind thinking positively, instead of worrying about mis-hitting it.

Payne Stewart used to work on a drill during which he would hit 5 shots with his SW and then 5 shots with his driver, with a conscience effort to use the same swing for both clubs, tempo-wise, and intensity-wise.  We can all agree he was one of the best drivers of the golf ball in his day.

Jason

My swing thought for all clubs is to let gravity take the club back down to start my down swing. Just kind of let it drop back on plane. This stops me from getting too aggressive too early. The attack starts about when my hands get to my right hip. When I don’t do this, I swing too hard, way too early and hook everything.

Hips, hands, club is another good swing thought.

Scott

Whenever I'm having troubles on the range mechanically or where I know what I'm doing wrong, I'll slow my swing way down to were it's just a slow smooth tempo (watch Ai Miyazato's tempo) and getting the right feel. Since you're struggling with your transition, try to take a slow smooth swing and work on that. And obviously as results get better, speed it up to your natural tempo and just hammer balls to groove the feeling you want. Hope this helps! And good luck out there!