Need a little advise.

Here's the scenario. I have always been around a 12-16 handicap. when I was younger i could get away with some mistakes since I could hit the ball a long way. Now that I'm creeping toward 50 I decided to change my swing a little to become a better ball striker with my irons. Thanks to all the great info on here I have gotten much better with my solid ball contact. The old problem was every round I would hit numerous shots "fat" due to lagging behind on the swing. After watch videos on proper angle lean for the shaft and getting more weight on my front foot I have been hitting the ball solid and long.

Now lies the problem. Since I have made this adjustment I hit everything about 20 feet to the right like a straight push. then when I go and aim left to compensate for it I hit the dang thing straight as an arrow left right where I was aiming. Any advise?

strange one, I would say the reason for the push is that because your trying to get shaft lean your right hand is probably less active in the release, in your old swing your right hand was probably scooping the ball up.Id try a split grip to try to wake up the right hand again.Odd  how you pull the ball when you compensate maybe just coming over the top with the right shoulder.But in conclusion id say stick with the shaft lean but try to wake up the right hand, o and check your grip is spot on.

General rule of thumb is if you set up to compensate for a ball flight flaw, then said flaw will disappear immediately upon impact.  I have a friend who follows this pattern (and is proof of the mythic law) with his driver:

First tee:  Lines up slightly to left.  Slices OB

Second tee:  Lines up aggressively left.  Ball in fairway

Third tee: Lines up aggressively left: Ball in RS rough

Fourth tee: Lines up ridiculously left: Straight shot into the woods

Fifth tee: Lines up slightly left.  Slices OB...