I know it’s difficult to hear but there might not be all that much you can do. If he ‘s not ready to quit then there’ s small likelihood he will. (more likely to keep using but start lying about it).
The good bit is that on average a cocaine habit burns itself out over the course of around 5 years.
Keep a tight check on the finances ; seperate yours from his if you ‘ve got joint accounts ; but mostly just TALK to him.
Get him to tell you why he feels he needs to take it, what it does for him, what he thinks he gets from it that makes it so worthwhile.
Addictive behaviour has a motivation. It doesn’t happen because the drug has some magical power to compel someone