All of this advice is getting way to complicated. someone mentioned paralysis through analysis. That's why I recommended what I did back in my original post.
Also many people are recommending what their pro told them. Murray's problem may have nothing to do with your problem.

It is usually better to just go through some drills and get your game back to where it once was and possibly better with as little thinking as possible.

And by the way, please don't try to keep your head down. That is one of the worst pieces of advice ever given to a golfer. I have spent hundreds and perhaps maybe thousands of hours trying to get people to move their bodies correctly because they were stuck trying to keep their heads down.

Well I had my worse round of golf this year. it is very disturbing when your body does not do what your brain knows it is suppose to do. Its time for me to reach out for help. Calling my pro in the morning.

It was so u gly out there today

Interesting post. You have discounted the information people provided based upon what their pros told them since "Murray's problem may have nothing to do with your problem", even though the OP specifically asked others for input: "For those of you who have gone through this, what was likely cause? What checks have you instilled in yourself at set up etc. to prevent this happening again?" And then you point to your own input as something the OP should go back to and review. I am not discounting your input as I agree with your statement, "paralysis through analysis", but I am amused at the "double standard" presented.

See one of the pros.