heya, just came across this article:http://www.sciencedaily.com/releases/2012/05/120507210042.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A
it's rather sciency but this paragraph might help:
"We believe that the alterations in insulin secretion could possibly be related to the increased carbohydrate cravings and weight gain experienced by many smokers who give up. However, the increase in insulin secretion and carbohydrate intake seems to be a transient effect of stopping smoking, as these changes were not seen any more after six months, even though the participants had gained more weight."
essentially your metabolism changes (from what I gather, you generate more insulin and your sells become somewhat insulin resistant or something) but these changes peter out / revert to normal after about 6 months...
so er... well keep it up and have hope, after 6 months your body will no longer excessively crave carbohydrates.