You're absolutely correct in that your boyfriend is suffering from depression, and with good reason. The problem is, he has to want help, to get help. Can you or somebody in his family talk to his doctor about what your boyfriend has told you about his feelings?
I'm sure you can do it. Just make sure the doctor understands that your boyfriend doesn't want to talk to anyone about this, and his doctor can make it his idea, considering the circumstances. Just call his doctor, you're only looking out for his well being, and tell the doctor that you're not asking to have any of his health info, but that you feel he needs to be aware, and could he somehow address this with your boyfriend?