It is not your responsibility to be his moral compass. And no you should not be telling his doctor, that is his to own and a choice only he can make. And it is really important for him to learn by his choices.
Sadly you don’t have the power to keep him clean, safe, or alive. You shouldn’t be his safety net, his I caught you in a lie, or any of that either. And the drug testing, way icky!
What you should have are your own boundaries…
Instead of a need on your part to tell his doctor which is unhealthy all the way around no matter how one justifies it.
You can place a boundary of I can not live with anyone who is not honest in all their affairs no matter the reason, even a legit one. Then You follow through. Then it is about you, what you need. And this isn’t to get him to do anything, but to find what YOU can and can’t live with.
And FYI, loving someone unconditionally should be a should, but it ends right there … it is good for your soul, and about you and way better than being riddled with anger and hate for another. Nothing is really about him. And staying in the marriage has nothing to do with unconditional love, nor does leaving mean one doesn’t.