Don't Rotate Your Left Arm on the Backswing
When I was in Florida, I was taking lessons from PGA professional (teacher).
He asked me to rotate my arms to right. I tried it many times, but it just wasn't working for me. I lost distance. I didn't feel like I was adding power.
I think that it's not natural to rotate your left arm left on the backswing. I don't recommend you to try it.
There is not one correct golf swing for all golfers. If you think it doesn't work for you, you should quit trying it.
I write all kinds of drills, methods and tips on this site, but I don't think every one of them will suit every one.
My hope is that you find at least one thing or a tip that will help you improve.