It sounds like your hands are getting ahead of your body and your to far away from the ball. Since the heal of the club is taking the divot it means that your stretched out enough the toe is lifting off the ground.
You said you felt like when you brought the club in closer that it was to close. My guess is if your hands are ahead of your turn that you need more room to make the swing as your torso isn't allowing your club to come from the inside.
You may be only shanking with the really short
irons as the swing is shorter with these
clubs and you stand closer to the ball.
Shanks are a nasty business that need to be worked through. Try to get some advice from a lower handicap player that can watch you or a professional.
If your at the ranch with a higher handicap friend. Hit about 10 shanks with him watching then let him hit. Shanks are contagious for the high handicappers and watching someone else do it will make you feel better.
good luck.