Do you have candida? It can cause you to crave carbs - especially stuff like bread, potatoes and pasta, as it lives on sugars and yeasts, and those carbs are a super source of readily available sugars.
Read up on it on the Candida Forum - it may be why you crave carbs.
Or it may just be a case where if you cant have it, you just want it 10 times more!
I am not sure if my inability to leave carbs alone is due to the yeast or weak will! i am in an area that i am unable to be tested for it , however i do have classic candida symptoms. hoping its candida and not an entirely hopeless will!!