I have discovered that managing any addiction requires a day-to-day approach.  I stopped smoking tobacco (and, other things) by weaning myself down, first.  Whenever I felt the "trigger" to light up, I'd say (out loud, sometimes), "I don't need this, right now.  I'll finish my conversation and then I can light up."  I did this over a period of weeks.

Then, I made a committed date on which to stop smoking for that day.  I didn't smoke the entire day or evening.  I did the same thing the next day, and so on.  It also helps to have the support and encouragement of people who are ALSO managing a smiliar addiction.

Treatements centers make millions on a short-term basis.  Yes, they can teach behavioral adjustments and trigger management, but they are not a "cure," by any stretch of the imagination.  There is no "cure" for any addiction and it is successful when approached on a daily basis - sometimes, a minute-by-minute basis.  To accept that fact is the first and most important step to recoverying from any addiction:  there is no cure - there is only management.

Even now, I still want "just one" cigarette.  I completed the physical withdrawal within 10 days, as you will when you stop smoking weed.  5-10 days is the typical withdrawal for the physical aspects.  Then, it is a lifetime of management, thereafter.  I know that one cigarette will lead to five.  Five will lead to a pack, and a pack will lead to another round of withdrawal after months of denial and self-harm.  I know this.  I don't ***like*** this, at all - I see many other people who can apparently smoke sometimes three a day, and go on with their lives.  Me?  I'm an addict to tobacco and all of the chemicals in cigarettes.  I make the choice to not smoke, daily, because I "accept" the fact that there is no cure for any addiction.

Look into Narcotics Anonymous (NA), along with AA (Alcoholics Anonymous) open meetings, and any other support groups.  Beware, however, that support groups with other addicts can backfire when addicts get together and undermine one anothers' sobriety or remaining clean.  It's a 100% personal choice that can be managed, but it can only be managed by the addict.  Period. 

Good luck to you and brightest blessings of recovery.