I wouldn't bother fighting with him over the phone. like, clearly a logical or emotional plea isn't going to move him, and he's gonna keep doing what he's doing. I know he's your husband, but dude sounds like a prick. It's one thing to relapse with a partner that has the same disease (addiction), it's quite another to relapse, hide it, lie about it, then fight more for the drug of choice than the partner and risk dragging them back into it.

I don't have any real answers, but you definitely didn't do anything wrong, unless you consider standing by one's spouse to be wrong. If it were me, I'd see about cancelling the entire cell plan and getting a new number. If he can manage side pieces then he can manage paying for his own shit too. Just my $0.02.