Once shame is internalized, we do not feel shame, we feel we are it. Bradshaw says, "Once internalized, we no longer have the feeling of shame -- we are it. Because we experience ourselves as flawed and defective, we cannot look at ourselves without pain. Therefore, we must create a false self." For more detailed information, I highly recommend getting a copy of John Bradshaw's book, "Healing the Shame that Binds You" and reading pages 82-86.
This book has done so much for me, even though I don't have chemical addictions. I have any anxiety one though!