If it helps - his feelings and expression of them are extremely common. The Samaritans even had a poster campaign with the slogan "I don;t want to die, I just don't want to live anymore ..." which is not the contradicition it appears to be - as any depression sufferer will tell you.
Feelings of desparation, and a need to take some action to end those feelings can lead to talk of suicide, but hopefully we are a very long way from that final step.
Knowing he is loved and supported helps - and the knowledge that you realise that this 'dark side' is not the real him that you know and love.
Sadly, depression makes you hate yourself, and when you really hate yourself, you can do a pretty good job of making sure that those around you feel the same way!
But as i said, it's not real, and it won't last, so hang in there, and you will get past this.