Coke is called the sly drug, and thats exactly what it is. You think you have it under control, then BOOM you havent, and there’s nothing you can do about it, and at the time you are in complete denial that there is a problem. The fact that you think he has a problem, and he doesnt is enough. If its a problem for you, then its a problem.
Its really for you to work out whether you can live in it, or whether you can demand an ultimatum. If he’s not an addict he wont have a problem stopping, my guess is, he won’t want to try because in his current state of mind, he’s not addicted and you’re blowing things out of proportion right?
I feel empathy for what you are going through, and I hope you find a way through this, sending hugs