You should go and see a pharmacist about NRT. I tried to quit a few times using patches (too expensive), Allen Carr book (didn't work for me), cold turkey (went insane!) and then eventually I gave up trying to give up! I heard through a friend that chemists can give you discounts on NRT products if you see them once a week for 12 weeks for about 2 mins each time to chat about how it's going, or longer if you need the support, and to pick up your NRT supply. I got the inhalators (cost me £5 for a big pack which lasted me more than a week) and they worked so well for me. I smoked 20 cigs a day for almost 8 years but I only used 2 or 3 cartridges a day to satisy the cravings, pharmacist had recommended I use up to 6 a day. I used the inhalor for about 4 weeks, using it very rarely in the last week or so before eventually quitting NRT and officially becoming a non smoker!
As for the diet.. I kept on it and used free foods etc to take my mind off of not smoking until I eventually didn't get cravings. I came off SW for a few months when I moved house and got sidetracked but I never even thought about starting smoking again