Can't I just cut down?

It’ll help somewhat to cut down, although this of course depends on how much you were smoking originally, and by how much you reduce. Research shows that heavy smokers (15 or more cigarettes a day) who cut their cigarette intake by half, but didn’t quit, did not have a lower risk of death. Quitters, however, had a 35% lower risk of death from all causes, and a 64% lower risk from tobacco-related deaths than those who continued to smoke heavily.

The researchers also found no difference in respiratory disease or death risk from heart disease between people who reduced their smoking and those who continued to smoke heavily.

Read more:
Ways to quit smoking