Here's Grivs video on shoulder placement. It's the second part of the video.
I'm not really a fan of going to a tension or hinge to fix target panic. I know I'm in a minority with that but the issue is mental, not with the release. You need to pretty well relearn your release if you truly have it, that's what the hinge will do, but it doesn't always fix the problem. It takes repetition, lots of it. People recommend blind baling, I'm not big on that either. I like a big target that you are close to. Need to have a big bullseye that is easy to keep the pin in. Do something like a 50cm field target at 8-10 yards. Makes it so your pin doesn't float out of the center. Shoot and shoot and shoot. That's the thing that helped me the most.
Lots of recommendations to pull your sight, that's just avoiding the problem. You need to shoot everything like you normally do, just get the reps in to retrain your mind. If you make the target really, really easy, you won't need to fight it. You can just shoot and retrain.
With my comment about the level I wasn't trying to say it was that simple, it's just something that I found to be a trigger to the TP. I think lots of little things can be a trigger. If you can identify things that cause it, you can help prevent it from coming back. It's like an addiction, it never goes away, always lurking. You need to stay on top of it.