I personally don't believe coming out of the fog is just about withdrawl, sure when you come out of that there is an emptiness that surely is like chemical withdrawl, but if we are talking about affair fog, coming out of the fog means realizing the consequences of your behavior.
It is one thing to be hungover the morning after a good party, is a completely different problem when you wake up hungover, evicted, unemployed and without clean clothes and the only thing you want to do is drink some more to escape the misery of the wretch you've become.