I agree with Magicblue to an extent. I think the girl in the song has a lot of "issues" that she dumps on him ("With all your love you gave to me, it was a mess ...") "What's slowly dyin' in me," is his love for her adn the hope he tries to keep alive that they can make the thing work. He knows it's not going to get better, and isn't able to convince himself otherwise anymore. The slow, mournful part in the middle is him finally losing all hope, and realizing he's done all he can. Then, when it picks back up, he's getting mad at her for treating him as she has, and at himself for letting her, and finally telling her off, adn not to bring her BS around anymore and just leave him alone.
I agree with Magicblue to an extent. I think the girl in the song has a lot of "issues" that she dumps on him ("With all your love you gave to me, it was a mess ...") "What's slowly dyin' in me," is his love for her adn the hope he tries to keep alive that they can make the thing work. He knows it's not going to get better, and isn't able to convince himself otherwise anymore. The slow, mournful part in the middle is him finally losing all hope, and realizing he's done all he can. Then, when it picks back up, he's getting mad at her for treating him as she has, and at himself for letting her, and finally telling her off, adn not to bring her BS around anymore and just leave him alone.