Good for you-I am not sure that I'd consider last night a 'backslide', like you said, you will eventually have to talk-and yes-it will be uncomfortable. It sounds like his eyes are really beginning to open up as to the amount of pain he's caused and may still be causing (the phone calls...good that he didn't answer).
Like you said tho, get back on that DB horse and "Charlie Mike" (continue the mission - C M). You're still doing fine but maybe consider backing off a bit-give him time to digest everything you said to him, let it sink in. Don't go dark but just give him some time. Continue doing what you've been doing.
