It is definitely that dark depression he's experiencing. It was an effort for him to be up and ready to go at that time of the morning, but he knew you and your son had to be at work. I think he must sleep a large majority of his time.
The desire to eat is another sign too. They tend to eat very little and I think he's being honest w/you about the drinking too. It's an effort for them to do much of anything.
It's really sad that he can't get himself motivated and into a doctor's office. The AD's would help level his mood off and maybe help lift the fog just a bit.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
