Hi Beck, welcome
What a great friend you are.
There isnt a great deal you can do. Insist that when he's ready you'll always be just a phone call away. Remind him you are willing to listen.
These threads might help. Use google
Topic: talking to men, some tips- beyondblue
Topic: the art of listeming- beyondblue
Topic: depression, a ship on the high seas- beyondblue