Thank you everyone, I really appreciate your thoughts and advice.
I guess I asked these questions in particular in order to try to understand what he is thinking and more or less, why. A lot of what he has been saying puts the blame on me for the faults in our marriage. Perhaps that is his denial coming forth through manipulation? I also wanted to clarify what I already knew regarding substance abuse or confirm his "current" beliefs. I am relieved to know that my knowledge and instincts are accurate.
Even though I may have contributed to this by not being as supportive as I should have when he first started to slip, it is ultimately up to him to choose his path. Anything I say or do to bring him back to the light will not be absorbed. The whole situation saddens me because I am seeing him slowly destroy himself and our family. I have to take care of myself and my daughter and try to blossom serenity in our lives. Whether that is with him or without him is for me to decide based on whether or not his behavior becomes unacceptable. I guess only time will tell.