Yes Day 3s can definitely be quite tough. The positive I'd take away from your slip is the recognition of the lack of relief you felt, coupled with the accompanying feelings of guilt and despair. I'm working with a young woman right now who just slipped after almost two months of not drinking. She described it almost verbatim the way you did. I think drugs and alcohol turn on us at a certain point, with her and yours experience being a testament to such.