[contingencies]

That's expected: I'm yet to meet anyone who can work effectively during withdrawls.

To resolve, just leave yourself at home or at a hotel with nobody else, a decent TV serial (BBC's various history documentary series are a great go-to) or computer game and food, and admit it will take three days for cravings to subside. It helps a little if you exercise. It's actually really easy, once you've succeeded once.

The real key is then not putting yourself in high risk situations (ie. drinking) for a week or two, because any time you restart is usually because of that. That was my hardest hurdle.

It can help to sync the quit with a change of environment or heavy endurance exercise (eg. multi-day hiking/cycle-touring which helps clear your lungs). Don't try to quit while stressed out at work or on a short timeline, that's just self defeating.