One thing about rock bottom is that it’s a neverending pit which as many levels.
We wasn’t even my ex’s rock bottom. I think addicts say all this about “I’ll get help bla bla” until the wife once again forgives and the shitshow continues.
It’s all in the action and actually doing what they say they’ll do and not just spout words.
I think you’ve done all you can do to help whatever he was to you. I doubt you’d know when he is using or not if you are not around him but the fact he is on the missing list suggests to me quite likely he is actively using.