I'm addicted to nicotine as well, I don't smoke, but have been "dipping" since I was 13 or so. I have also quit nicotine for a year or so, when I quit drinking. I obviously have a very addictive personality. I too adhere to the low carb diet hence the vodka and lite beer.
Obviously it is in my best interest to quit all of the chemicals, but when you live a lifestyle for 25+ years it's hard as hell to just up and change, even if it isn't an addiction, it became a way of life just for the sheer number of years I have drank and chewed. It became my persona. But now the sober persona seems to be fitting me pretty well!