Hello thanks for asking from HCM Nicotine is the main constituent of tobacco and it is a brain stimulant substance. Chronic smoking results in development of tolerance and dependence. After cessation of smoking individuals may suffer poor focus, lack of concentration, irritability, anxiety, restlessness, craving for nicotine, brain fog or dizzy feeling etc symptoms. These symptoms even persist for long time after quitting smoking. So the symptoms your husband is having are because of withdrawal of nicotine only. To prevent these effects it is advised to patients to chew nicotine gums for some time and then tapering the doses gradually. Nicotine gums are difficult to chew because of their bad taste. Other drugs like Bupropion, Veranicline etc can be used to decrease anxiety and craving due to tobacco withdrawal. Consult a psychiatrist for prescription and help. Thanks, hope this helps you.