Mike,
As you note, target panic is a mental issue. People, including me, have tried various ways to solve the problem, and I'm glad switching to left-handed shooting worked for you. I wonder why it worked?
My theory, which is worth exactly what you're paying for it, is that it is working because you are more aware of your bodily movements when you try something new. Increased awareness of body movement is a key to improvement in any sport, and also, by the way, focusing your attention on body movement means that your attention is not focused on destructive thoughts that cause target panic and other mental barriers to good shooting.
Try not to lose this increased awareness of body movement as you become more comfortable with left-handed shooting, and maybe it will help you to keep target panic away. If you can continue to focus on awareness, without consciously trying to control your movements, you may get to the point that you don't have to see a missed shot to diagnose what you need to correct; you'll be able to feel the difference as you draw the bow and can let down before you shoot a bad shot.