Smokers usually have to try several times before they quit for good, but it sounds like you're actually pretty close (addiction 'lite').
If your own health worries don't do the trick, I hope you're aware that both side-stream smoke and traces of smoke in your hair and clothing and skin can transfer those harmful chemicals to your precious child. I grew up in a household with three adult smokers, and have had a dreadful time with asthma and other lung problems my whole life. And I'm statistically at greater risk of cancer than a child who hasn't had my exposures.
But consider this: instead of trying to scare yourself, how about creating a positive mental picture of a loving mama with sweet-smelling breath and hair, shining and bright with your beautiful, healthy child in your arms? For me, working toward something positive works better than avoiding a negative.
Good luck – you can do this!