I actually gave it up a few weeks before I found out that I was pregnant because the smell of the smoke started making me nauseous. It has been very easy for me to stay away, but I can't say I was an avid smoker when I did. If you are struggling and can't just kick it, reach out for resources among your OB. There are always support groups and techniques they can get you to that will make it easier for you.
I was like u and I gave it up cold turkey.