SURPRISE! Unexpected first pregnancy

Well I just found out I was about 6 weeks along, and it was very very shocking as I was not attempting to get pregnant. Well I have a few questions 1 I am a smoker (obviously I quit when I found out) but has the fact that I smoked before going to harm the baby? Also it's very difficult to resist the urge to smoke, any tips that can help take the edge off? Since this is my first baby I'm pretty paranoid, I was also drinking before I found out (no drugs) since this all happened so early in the pregnancy should I be okay?