I suspect you feel like dirt because you haven't forgiven yourself yet. Forgiving yourself is much harder than forgiving someone else I have found. God will forgive you, this I know. You will find your own way to let yourself feel that forgiveness and to truly forgive yourself.
Going forward time and work will help your family. Family members can heal for any damage done. Perhaps suggesting that your family go to AlAnon or get into individual therapy will help them as it has helped so many of us.