I'm gonna sound like a clown here...
Previous thread is about casting. You have an out to in swing - not dissimilar problem.
Google Leadbetter baseball drill.
That gives a great feel about keeping your swing natural.
Give it a try.
Reasons I mention it:You would prescribe a baseball bat drill for someone who has as flat and deep backswing as that? really?
Going on the picture id say
Try to keep some flex in the right knee on backswing.
Try to watch some videos about keeping the arms synced with the body. (dan Whittaker hands in front of body would be a good start)
If reverse pivot then set about fixing that.
Possible grip issues if big pull from shut face.