I literally registered on this forum last week so he might not be a million miles away from where I am.
Recognising you are not doing the right thing when dependant on drugs is one thing, it’s having a single solitary idea what you can do about it that’s a massive hurdle.
There are relatively good options through a GP if the effects of coke are what your fella craves. The American brand name of a good substitute is Adderral, it has similar effects on the central nervous system as cocaine but in a much more manageable way, its cleaner ( as the efficacy of cocaine is a real lottery based on the cutting agents it contains) and it is far easier to monitor and therfore taper off, plus its free which is so important for you as a family. Biggest improvement I’ve had is telling a gp who was able to provide a decent alternative. Perhaps make yourself a GP appointment without your man present when all this corona thing is out of the way and ask what he or she would recommend?
An effective, clean substitute combined ( eventually) with therapy to deal with the man’s childhood is out there to be found. As I said I don’t know you and as humans our personal circumstances are SO intense and complex that it’s impossible to recommend a course of action but I hope you guys find it and it’s awesome that he’s got a lady out there looking for solutions. Keep at it and ( if you can) keep smiling OK.