firestorm it took me at least a month sober before the fog started to lift, my brain was not used to working without it's alcohol. Studies have shown that alcohol messes with the brains chemistry, the more one drinks and the longer one drinks the longer it takes for the brain chemistry to return to normal.
I had a ton of Dooh moments in early sobriety, but I promise you if you stay clean and sober it will get better. I saw noticeable improvements in my mental facilities for over a year, every month I would think to myself "Man this is awesome, it can not get better." and it would get better!!!
Studies indicate that binge drinkers actually whack their brain chemistry in some cases then every day drinking drunks like me, as to the recovery time for a binge drinker I do not recall if they discussed that or not.
I would suggest reading either "Beyond the Influence" or "Under the Influence", both books discuss the vast majority of things that alcohol does to us and also recovery.