I need help/advice

My SO smokes, and he has been for most of our relationship, but he told me that he was quitting, so I believed him that it was a goal of his (he has mentioned a few times that he doesn't know if he wants to, but I figured he said that due to stress because he was still cutting the number of smokes he's been having). Anyway, we decided to try for a baby, and I'm pregnant now, im 20 weeks. And we got into an argument last night over his smoking and he told me that he really doesn't want to quit and that's why for the past 6 months he's been staying at the same number, and he told me that I'm controlling and always on his back about it. And I told him that I don't see how smoking is so important to him, he quit once before, and smoking does nothing for you, it destroys your health, my health, the baby's health, our bank account, and his time. It smells bad, you cannot cover the smell, and it's gross. It literally does not one good thing for him, but a million bad things.