Make sure you continue your healthy habits and stay away from the second hand smoke. SIDS as well as second hand smoke dangers to you and you baby are important considerations in maintaining health for both of you. There are good prescription options for quitting smoking if your husband is willing to discuss them with his doctor. Chantix has had great success and well as Wellbutrin and quitting will keep him healthier for his baby too.
Good luck!
Please find some of the literature on sudden infant death syndrome. Babies who are around people who smoke have an increased risk of SIDS, even if the smoker does not smoke around the baby. Give the brochure to your husband or print out what you find online and show it to him. Google "SIDS and smoking." If that does not make your husband care enough to quit or at least to go outside to smoke and to change his shirt before holding the baby, I don't know what will.
I don't know what you should do, but I will tell you what I would do...have him smoke outside. Even secondhand smoke is bad for you and the baby, both now and after the baby is born. The past drinking shouldn't affect the baby. Smokers made a choice to smoke, and I don't believe smokers when they say they can't quit. After smoking for almost 40 years, my grandmother got very sick and quit cold turkey. She had cancer. And lest you think it was too late...they took out 2/3rds of one lung and she is still alive 20 years since the surgery. Of course she has COPD, and she is on oxygen because she waited so long, but she is still alive and got all that extra time. Another woman I know, who is now in her 50's, he mouth cancer from smoking, and that is a death sentence. She might have 6 months if she's lucky. Quitting is hard...there's no question, but people do it every day if they want it bad enough.