I posted something similar earlier this morning that might help you.
I don't think Chantix ever knocks out the desire to quit. What it does, tho, is once you actually put the smokes down, clean the ashtrays out, etc., it changes the desire.
In the past, every time I've ever tried to quit, I was going out of my mind for a cig. It was totally consuming.
Chantix makes the desire a bit different, but NOT WHILE YOU'RE STILL SMOKING! Once you are of the mindset that you're "in your quit," Chantix makes the desire for a smoke very manageable, almost like just a passing thought. After the first few days, the desires again become even more manageable. Once I was through hell week (the first week actually quit), I'd liken the desire for a cigarette to that of a desire for a pizza, a funnel cake, a Corvette. Sure, one would be nice, but it ain't the end of the world if I don't get one, you know?
Really, what you're going through right now was the worst from my experience. You're dreading your quit date, your brain is not getting satisfaction from the smokes (from a nicotine receptor standpoint), your body is getting used to this strange foreign chemical you've introduced to it and you're exasperated because you probably really don't know what to expect tonight, tomorrow, next week.
Believe me ... it gets better, MUCH better. But Chantix will never get rid of your desire to smoke. It just makes it so that once you don't have a smoke available (which you're not experiencing right now), you're not going positively out of your mind for one.
Read the stories here for more encouragement. Everyone here has been in exactly your shoes, including me! In a couple months, you will be writing a message just like this to someone else
BTW, I was a 20-year smoker, up to 2 1/2 packs per day for the past five or so years. I quit smoking on 5/22, and I quit Chantix on 6/22. Still smoke-free and Chantix really made it possible. It's work, yes, but Chantix is like novocaine at the dentist's office for a filling. It makes it tolerable