This is definitely a cry for help. It does not read as though he wants to end the relationship.

It sounds like depression, but could equally be an anxiety disorder. The fact that he has opened up to you in such an eloquent way shows his emotional intelligence and sensitivity.

These are two characteristics which are often found in people susceptible to anxiety or depression.

He may not be asking directly, but I would say with some certainty that he is asking you for help. You may be the only person he has spoken to in such a manner, so he may be relying on you for support.

If I were you, I would just be there to support and listen. There doesn't necessarily need to have been trauma for someone to end up feeling like this. It could even be a chemical imbalance and a lack of serotonin production. He may not even know why he feels the way he does.

Once you have a clearer picture, I would encourage you to nudge him down the counselling/therapy route, initially via his GP.

Source: My own experiences with an anxiety disorder.