A person has to want to quit for themself. They will never do just because you love them and want them to. They will lie about it, they don't want you to know they are dong it. I think he knows it hurts you, and thats why he lies. I was married to an alcoholic... I'm not anymore I couldnt stand it anymore. H e said when we had our son he'd quit... He didnt... We had fights i called the cops... he didnt quit....Now he lives with his mom and still drinks, lost more than one job....
You may love everything else about him, but the drugs are gonna be there and they are hard to get rid of... The drugs are bad, they will ruin you, your hope of a family. And quite possibly kill him....
Don't try to make him quit to be with you, he's got to want to do it himself or it will never work...