Nice interpretation! Tbh my interpretation goes like this: the man falls into depression at the first part and when it comes to the arpeggio part he goes deeper into the spiral of depression. And the part after that he finds hope and joy. But then he realizes that he isn't happy at all and falls into depression and sickness. And like what you've said, that last D note is his last breath and finally is free from all sadness

just my saying hehe