It sounds like you have made great progress in a short time. My advice is to ask your physical therapist/occupational therapist if he/she knows of any colleagues in the department who hunts or shoots. You may be able to get some very focused training on some of the important mechanics that you need to work on. They may be able to help you by simulating your shooting technique or possibly refer you to someone who can help. When they observe your body position when shooting, they can provide pointers and suggest mechanical aids like cushions, wedges, braces, etc…. Don't give up on your passion. These professionals are dedicated to helping you.
Good luck and have fun.
Warren