Smoking cigarettes will not help you lose weight. Yes, smoking is an addiction and like any addiction will occupy your time, but it will not help you lose weight and if it has, then you are fooling yourself. Why? Because you can become addicted to anything, NORMAL. You do not have to sacrifice your health to a "supplement". Here's the solution. I believe that addiction is normal to some extent. I believe Heavenly Father put these strong feelings in us to enjoy life. But like any matter, Satan can distort that virtue. That is the only way we get good at something because we create endorphins in our successes. So instead of smoking, find something else to occupy your time and have it become an addiction. Especially Family History! It becomes an addiction, you just want to find more! Yes, we all need to "relax" sometimes, but trust me, sooner or later you will find that there are different (LASTING) joys to experience in life that you have never experienced before and you will not want to sell yourself short. Think long-term.
My addictions: reading the Book of Mormon, running, Family History, yoga, art....
Scary thoughts: Are you experiencing more trials in life related to feeling down about life or are you experiencing more trials pertaining to your growth such as learning a new language, christlike attribute, or instrument?
Play the game of Would You Rather with yourself. You'll find that you are sabotaging your life than you thought. Ex. Would you rather have a cigarette and be late for work or go to work on time and get a raise. If we think about the long-term and weigh the consequences of our decisions, I think we'll find that we'd rather choose the better way.