Hugs to you during this tough time.
He's a big boy...you can't cushion his fall.
The good news he is sober and will be able to make wiser decisions about his divorce.
The fear of losing visitation may motivate him even more to stay sober.
IMHO: Offer him a shoulder and an ear, but don't offer to take care of it for him.
We all get stronger and more responsible by flexing our emotional muscles...