Probably right about the alcohol.
I quit about 25 years ago and I had to quit drinking for the first few weeks because I had an automatic habit of open a beer, light a cigarette. I don't remember being particular nasty while quitting, but my wife can tell stories that beggar legends... In any event good luck with it. I still don't think I feel any better for quitting but it's a LOT cheaper I still have a pack of Parliaments in the freezer that I bought for 98 cents; I quit when it threatened to go over a buck a pack. And I don't really remember how I felt a quarter of a century ago since I have an entirely new set of afflictions, but it was probably for the best.