rasue, I just went through something a little similar.
My oldest is in a halfway house clean. He called me crying that he just can't take this place any more! I listened to him and told him I love him and that living there is not forever.
It seemed to calm him when he realized that.
I know it's not exactly the same as your son's situation. I like Japic's comment. That's a perfect thing to say!
Encourage him always.
Hugs to you.