My grandmother was my best friend. She was an amazing woman that would do anything for anyone. On February 6, 2013 she passed away from cancer at 70 years old. She has smoked since she was about 16 years old. When she got to be about 55 she was on oxygen continuously. She slowly stopped being able to leave home because she couldn't breathe. It was completely awful.
She had a stroke back in 2010 and they told her to stop smoking. She did for about 2 weeks, but once she was released from the hospital she started back again. Eventually she went to see her physician and was told that if she stopped smoking it would kill her.
That was heartbreaking news since she could barely move without running out of breath. She was very important to me and now I no longer have her thanks to cigarettes. It's a tough habit to break, but it's even harder the longer you wait. It is best to stop as soon as possible.
Of course it is hard to just stop cold turkey, but maybe making a plan out to stop might help. Listing things off that you could do instead of smoking might help. That away when you do stop you can always go back to your list that you made.
You can even list out why you want to stop and you can always go back to it when you want to smoke. It could work since quitting cold turkey doesn't. If you have to make hundreds of lists, well it's better than being put six feet under because of a cigarette. They do take life's and they do not discriminate.