I believe you both are certainly on the right track. The beginning seems to be about some sort of muse, inspiration to write it. Perhaps through ups and downs, he found strength without her. Now he's offering that they change together, if she so chooses to make that choice with him. He is no longer the underdog, he is going to make the choices, and the changes, and it is up to her to accompany him or not. - This is just my interpretation!
I believe you both are certainly on the right track. The beginning seems to be about some sort of muse, inspiration to write it. Perhaps through ups and downs, he found strength without her. Now he's offering that they change together, if she so chooses to make that choice with him. He is no longer the underdog, he is going to make the choices, and the changes, and it is up to her to accompany him or not. - This is just my interpretation!