Smoking

Hi all. I just found out I'm expecting(around 5weeks). I started cutting back on smoking while TTC knowing that I wanted to quit, however, now that I'm pregnant I've tried quitting cold turkey and that didn't work. I could literally feel my stress level increasing. My doctor told me that cutting back and only smoking until the cigarette is half way would be the best alternative, because quitting cold turkey would increase stress on me and the baby. I REFUSE to smoke through this pregnancy because I didn't with my first and I so badly want to quit, so does anyone have any suggestions? I'm down to no more than three cigarettes a day. Please no judgement, I'm just looking for maybe some options that helped others quit completely. 
Thank you in advance!