Its irrelevant what problems others have incurred during their pregnancy even if they did everything right. And certainly not the OP's fault.
We all know the risks caused by smoking, whether pregnant or not and the OP has asked for help, not judgement.
OP, I stopped smoking 3 years ago when we started TTC. After 2 years and a late AF that I had convinced myself would result in a BFP I got so upset I went to the shop and bought a packet of fags.
I got my BFP about 5 weeks ago. When I found out I was pregnant I immediatly went from the 20 a day to 10 a day and am now on about 7 a day which makes me feel incredibly guilty. However I have set a date of 28 May to stop completley. I have been referred to the stop smoking support group and will get whatever I need to get me through this. I have told myself that I am not stopping forever, just whilst I am pregnant and BFing. This will make it easier for me to deal with I think.
I like smoking. Or I did before I got pregnant anyway. I did stop for 2 years and know I can do it, I just chose to start again after it seemed we would never have that baby. A consolation prize if you like. Now I have my BFP I have to stop.
Its not so much the risks of smoking whilst pregnant that bother me. Its smoking when I have a tiny newborn and increasing the risk of cotdeath by breathing smokey fumes over them. I read somewhere that if a woman stops smoking by 14 weeks by the time baby is born no damage will have been done. So am consoling myself with that thought.
Smoking whilst pregnant is a very taboo subject. Rather than insult people who do, if they were offered more support and help to quit it would be a lot more productive I think.
You need to want to quit to be able to achieve it. And if you really think you can't the seriously cut down. Start by reducing by 1 a day, every 3 days. Skip that second fag in a morning with your coffee, then the one you have when you get off the bus or in from work or whatever. Loose the ones you most associate with routine and go from there. Good luck.