I’d have assumed even OP is committing a crime, as a householder routinely ‘allowing’ a Class A drug to be consumed on the premises, and with bells on since there is a child present. (Not that I’m advocating for a prosecution)
There must be cocaine all over the gaff by now; forgotten/ emergency wraps hidden, traces on surfaces, and again, that child could happen upon overlooked powder somewhere and scarf the lot thinking it’s sherbet.
There is also the question of his dealer/s.
At some point, given the way he has lost control of anything money related, there could be an unserviceable debt hanging round his neck, and today’s coke dealers are not far enough removed from the violent gangs who import it.
Debts are often dealt with by attacks on the debtor’s family, and his house. The people who carry out these jobs are the very worst imaginable.
Involvement with cocaine dealing and consumption, unless you are very heavily buffered by money and social standing, is such a mug’s game, and it’s often lethal. For someone.
Is it lunatic of me to wonder can the local cops be spoken to, for advice? A Community Police Officer? I cant think of any other advisor.
Unless of course Women’s Aid would guide you out of this, and they've undoubtedly dealt with women who’ve suffered the many toxic effects of men addicted to cocaine. Maybe that, as well as a consulting a divorce solicitor of course, should be your urgent job.
You’ve all my sympathy, OP. I saw that accursed drug destroy a good few male pals when I was younger, and it still breaks my heart to think of them before it turned them into boiling messes, very far from the slick dudes they first thought they were after a few lines.
I hope you can find a way to get this man out of your lives very soon. Maybe he can be brought back to himself, and maybe even to you, with a commitment to rehab, but for now, he is a very serious liability and a threat to your safety.
Good luck x
PS apologies for turning a quick comment into ‘War and Peace’