A lot of times with us guys...Not talking means we are thinking.
We internalize everything where women tend to share and get it out.
Pissed off at self, the world, or just trying to put all the pieces together.
Same as a road trip. We won't stop for directions till it becomes an absolute must. It is a pride issue. I can do it without help...I am a Man.
You are seeing outward signs of inward struggles, most likely.
When he is ready, he will look for a sponsor and start working on his recovery.