I will offer my opinion, take it for what it is. One, visiting him every day is ridiculous. He needs to focus on why he is there and decide if he is going to work the program, or not.
You need to focus on you. His son is w/his mom, at this time that is likely the best situation. If he needs his son, he can contact his son himself. Yes, the daily life of it all is overwhelming. I am a single mom with two kids with an XAH who does NOTHING. We are all sick, and I am telling you I don't know if I am coming or going. However, my mom gave me good advise. Make a list, and just take it one thing at a time. Don't be overwhelmed with what you have to do tomorrow, just do today, this one task, right now.
He is in the right place if he is depressed. This is nothing they have not witnessed before, and may just be manipulation. Thing is, bad actions have consequences. Not everyone is going to be overjoyed to suffer those consequences. That means, he has to come to that his own behavior has caused this. He can pick up and move forward in life, or sit at rehab and cry about it. That sounds harsh, but it's reality.
In the mean time, work on you. Get a counselor and some face to face support for YOU. You deserve that. Step back and let him figure himself out.
Hugs to you.