Review your CBA

Think about both the negative consequences and the the pros of quitting. The SMART handbook recommends:

Review your CBA. It may not turn off the discomfort, but it may help you maintain your motivation to resist your urge. It may help to review it regularly, even when you’re not having an urge.

Similarly, in Changeology, Dr. John Norcross writes:

Remind yourself of the reason for your goal. Remember to use both sides (the two-headed push-pull) of the motivation: the push away from the disgusting behavior and the pull toward a brighter future. Such a process rarely stops a raging urge, but it powerfully reminds you of the psychological triggers in the past and the psychological payoffs in the future.

See also

Cost Benefit Analysis (CBA) and references cited there.