Hi there.
I tend to like this whole Jekyll and Hyde story as a metaphor, although I personally see potential dangers in it when applied to recovery. What you just described:
That person is not me, but I am facing far more pain and agony as the real me than I did as the careless, reckless, selfish, insensitive person
I think this is important to keep in mind:
I became when drinking
Perceiving it as "another person" has the dangers, in my opinion at least, that if you keep cultivating that, you might just throw a lot of other things "on him" as well in the future and not deal with them as a whole. What I am trying to say is that it might lead to further disintegration instead of becoming a more complete person who can be responsible for his acts anytime.
Just some food for thought.