So sad... I lost a friend this year to cocaine... he was 46, smart (software engineer), good looking (could and did have just about any women he wanted... made me jealous as he11) and except for the drugs and drinking seemed healthy.
Turned out he was drinking and doing coke 24/7... as you say he obviously had some demons to deal with... and didn't.
Finally his liver and kidney just stopped working (not a pretty way to go).
I'm ashamed to admit I used to snort coke with him back in the day.