The OP's junkie H doesn't want it to come out about his drug abuse because of the job he is in. In which case that must be either because it is about an abuse of privilege (medical professional?) or he has direct responsibility for the health, safety and welfare of others.
Here are the facts:
He is buying large quantities of meds currently legal but soon to be illegal off of the internet using his wifes name and his wifes credit card.
He is making her drive him to pharmacies whilst on holiday to buy meds even though she was sick throughout because of her own health issue.
He persuaded her to lie about a health issue to get more drugs for him. he will do this again.
Her own health issue means she is unable to manage her children and therefore she has a nanny to do this.
He is threatening to kill himself if it comes out about his addiction one minute and the next is shouting at her to shut up because he knows what he is doing - he is emotionally unstable.
He takes these drugs inside a locked study. the op has seen him crushing tablets up - to snort, inject who knows.
Despite all of the above the OP thinks that somewhere there is a magic wand that is going to wave over all of this and put it right. there isn't. Nothing changes if nothing changes. He cant change he is a junkie the drugs are more important to him than his own life.
so its down to you OP. you have to change the situation. I don't know how old your kids are or whether you are in hospital pregnant or whatever. but all of that is actually irrelevant.
you don't like people telling it like it is. And you wont listen to those with a huge wealth of experience either. so, I just hope to God that there is someone monitoring the parcels or that he has a near miss at work that is so significant that someone drugs tests him, or that the local pharmacies report him. or that the nanny reports him. because you sure as hell aren't going to do anything.
You know what is happening is wrong and you know you enabling it because you are an educated woman who can see this.
but its him first and everyone second. I hope that the Police and social services when they get involved give you the push that you need to sort things out.