Back To The Island lyrics by Jimmy Buffett

The person in this song is lamenting the fact that the relationship between him and the girl that he loves seems to have come to an end because he told her he wanted to go "Back to the Island", which can mean either a literal island or, more likely, be a metaphor meaning that needed some solitude for a while and she seems to have not taken it well when he told her that.
He feels bad and is hoping that he can get her to understand so that their love won't have to come to a rough ending, even though that seems to have already happened.