Much good advice. You bear a burden, surely. But it is one requiring you to forgive yourself as others have shared. Most mental trauma comes from unresolved guilt and personally not forgiving ourselves. It also blocks God from healing us if we refuse to allow His Ultimate sacrifice by not forgiving ourselves. Makes it hard for God to heal our wounds... I know I and many struggle with this same issue, so it's not easy, but we must keep striving to do so!
My prayers are for you and your forgiving yourself. Never forget, but live in acceptance as a Forgiven man. We don't know what Mr. Shinn's family is telling you, of course, but we're all mortals and regardless, Mr. Shinn now stands prefect before Christ and surely HE forgives you along with Christ.
Go in peace. Keep the Son in your eyes!