Many times, myself included, people look for causes in the wrong places. What was I doing at the time I developed target panic that caused it? Was I concentrating too much on aiming rather than shooting instinctively? Was I scratching my a$$? Years ago, my wife got into a traffic accident while making a left turn. Ever since then, she's had a phobia about making left turns, and will go way out of her way to avoid one. We don't need to analyse what caused my wife's traffic accident, but it wasn't because she was making a left turn.
The cause of target panic is very simple: we lose control over the shot; the shot is controlling us rather than we controlling the shot. Everyone who has been successful in overcoming target panic for themselves or others realises this: Joel Turner with Iron Mind, Rod Jenkins with the Bridge program, and Jim Casto with his program of repetitive drawing and shooting (you need a sexier name for your program than that, Jim). When we lose control over the shot, we need to retrain our brain to regain control over the shot.
You can probably design your own program if you keep the basic cause in mind and start from there. Start with doing some action with the bow that you are in complete control of, repeat often, and slowly work your way forward until you have complete control of the bow under all conditions under which you want to shoot. After you finish your program, if a situation arises where you lose control of the bow again, realise it for what it is and step back in your program until you can fully regain control of the bow again. Every time you shoot the bow from this point forward, you are doing one of two things: you are either reinforcing your control over the shot, or you are reinforcing the shot's control over you.