I have been smoking for the last 20 years and I really want to quit. I cough my lungs out every morning when I get up and then I go to the loo and light a fag. It's pathetic. This has to stop. I am contemplating trying nicotine gum. But I don't know if there are any serious side effects from the nicotine gum? Will I get cancer in my mouth as well in my lungs now?