You can do it.
The question is Do you want to do it?
We don't know you, so it's hard to know which approach will help you really. But you need to accept that this 'being stressed giving up is worse' is total bullshit. An excuse for some women to keep smoking.
With health stuff I work best when I'm scared into 'behaving' so we'll go with that. Read no further if you don't want to be scared into it.
Would you lean over the cot of a brand new baby and blow smoke in its face? If not, why is it ok because your baby is inside you?
One of you is going to have to go cold turkey, you get to choose if it's you now or your baby when they're born.
Google healthy lungs v smokers lungs and picture your growing baby in both those environments. It's not exactly the same, but near enough.
Read the statistics re cot death when the mother has smoked through the pregnancy.
There's plenty more out there to scare yourself into stopping. But you have to be prepared to do it. If not now, when?