First off I wanted to offer you a hug because anytime you are dealing with the trying to smoke issue, you need support.
I quit several years ago using Zyban, I was all good for about 2 years then hit a pocket of serious stress and fell off the wagon and started up again.
Well and I am not sharing this story to scare you but in the summer of 2003 my Mom who was 49 was diagnosed with lung cancer- she had been smoking since she was 11.
She ended up going through chemo/surgery and radiation and 8 mos after she was diagnosed she passed last February, 4 days after turning 50.
I smoked the entire time we were dealing with her illness but I promised both myself and her that when everything was over I would quit smoking for good. She had quit right before being diagnosed, talk about irony.
Anyway a couple of months after her passing, I went got back on the Zyban but this time I used Wellbutrin since I was depressed and immediately cutdown on the smoking. Long story short I quit and I am now pregnant with my second child, my son is 13 and when my Mom first passed he was so upset and afraid that I would die early because of smoking. It wasn't until her passing that I realized just how much of an effect our smoking has on our kids even when we think it doesn't.
I am now pregnant with the granddaughter my Mom & I often talked about yet it hurts so much to know she will never see this baby. I know how hard it is to quit but death by lung cancer is hard and I want to avoid such a fate at all costs. Death is a certainty in this life but I would like to live long enough to see my kids grow up and see my grandbabies as well.
I should also add I started smoking at 14 and when I was younger I too had no desire to smoke, however in all fairness my brother who is now 24 has never smoked and probably never will. So yes, some kids choose never to do it but I think you increase the likelihood of having kids who smoke if you smoke. Ultimately only you can decide how to proceed but I wish you luck!