Hi smartrose.
You didn't Cause it, can't Control it and can't Cure it (the 3 c's).
Your Husband is an addict. You know this. The only question is what are you willing to put up with, what are your boundaries.
Boundaries are for you by the way, not "rules" someone else has to follow.
For instance you may decide that you will not live with someone who is in active addiction.
Now that's your own boundary. You can share it with others if you want to, but that is not necessary. In this case you might want to share it, once you feel you are on solid footing with it.
This does not put the ball in his court because your boundaries, again, are yours, no one gets input on that. He will quit or he won't, if not, then that is your signal to exit.
Boundaries are so important, not just in addict relationships, but in life and it sounds like yours are being trampled all over the place here.
Do you want to live with someone that lies to your face? Someone sneaky that steals from you? That's just the part you see, what else is he up to, where does he get to? He's out doing drug deals, hanging around people who supply and do those drugs. It's like a separate life.
There you are and he lies about it. Tells you that what you know isn't true (gaslighting).
He makes me feel bad for him because he has no family support and has had to work from the bottom up to be successful
This is manipultion, pure and simple. What you said above describes millions of people. They aren't all drug users. One has nothing to do with the other.
Maybe it's time to hop off this particular crazy train?
Oh and please, protect yourself and stop trying to have children with this man. No child deserves to be brought in to a home with an active addict.