Why cant i cant quit smoking?

ive cut back quite abit .and i recently decided quiting .. but im sooo fuking nervous and emotional. i keep thinkg whats going to happen when iwant to drink or when im walking around to appointments i have .when im not occupied with something is when im smokign and also when others are smoking i find it automatic im taking out my pack. how the hell am i going to do this im already going nuts and ive only cutted back the smokes...???