The Artist is feeling Doomed & Heartbroken when his lover betrayed him. He Feels like his head is hung in chains with shame because he thinks that he is not enough or failed to provide the love his lover craves. Then he Sings/feels about his lover being his twin in every manner (not physically but emotionally).

Now that the artist(singer) says that he is gone (left this world) in the shame and left her with another man she chose.

He says that whatever he did to keep her love was in vain. He thinks that he is weak & very emotional to carry on with long lasting relationships, asking her if she feels satisfied and stronger with the other man.

He thinks about their love all the time but he let this love pass, like a stake to heart and fire this love will not last forever. He chooses to let it go.
She no more wants him and he is all heartbroken and doomed and unwilling to go on with this broken relationship.

He thinks that the other man could not love her more than he does and She has lost him and his love forever. He lost his life and she lost him.