Deep rhythmic breathing at every opportunity will help those tense nerves. And don't forget a deep breath with a tug on the ribs at least once, three times a day. Remember you are choosing not to smoke. Stay clear of your smoking friends. By all means keep your fluid intake high.
Fluids are essential in getting rid of all the tobacco residues.
Avoid coffee and tea which might trigger that craving. Furthermore, you are on your way to better health, a better lifestyle and lessening your chance of cancer and coronary heart disease from tobacco-related causes. The body has wonderful restorative powers. Give it a chance. You reduce your chances of heart disease, lung cancer, at least six other cancers and chronic pulmonary disease when you stop smoking.