A better way to say it would be using the leg to push the hip, here's a video of what I mean he's referring to the downswing but am I right in saying for the backswing should you do something similar, where you use your leg to push the hip rather than just trying to get the hip to turn clockwise
I'm sure if you look at about two years ago on this site, I mentioned somewhere that after having my first ever sub-80 round (a nice 77 in a tournament!), I failed to break 90 for I think two months. These things happen.
Can't hit an iron? What's the longest swing you can make with your PW and hit a good result? If the answer is a chip, go hit some chips and, after some good ones, expand into pitches. Similar with pitches into 3/4 shots, etc.
This is very likely something you can work out by going back to what you do well.