Is it my fault?

my boyfriend smokes alot of skunk (drugs) and its bothers me so for the past 5 months we have argued about it , ive gone to leave him a few times and weve made up and staid together but still when he smokes i go in a mood n i dont like it n it causes us to argue , he says he loves me n its just an addiction but its still no comfort, i told him that i didnt wana meet up wiv him cos i wernt feeling happy n we wud oni argue cos its doing my hed in , n he says well if u feel like that then dont meet me on the weekend cos im gunna b smokin , i sed well in that case i dow fink we shud meet agen n he goes nah i dow fink we shud cos its always gunna b a problem n i ent gunna give up yet n i sed fine av it ur way does this make it my fault that we broke up cos i always moan at him for it , p.s i have a baby on the way im 4 months am i rite not wanting him smoking?