Yes I Am 29 Weeks Pregnant And I Was Heavy

Yes I am 29 weeks pregnant and I was heavy user of marijuana before I found out I was pregnant I really didn't find out I was pregnant until I went to the doctors an she told me I was two months since then I have still been user of marijuana and smoke cigarettes how can I clean my system so that it will not harm my baby from me smokin I have tried to quite several times but it helps with my naseua but sometime when I smoke cigarettes I get sick to the stomach and throw up sometimes I am really trying to quite please help.