In the song, the guy problably gets tired of not being heard/acknowleged, despite his effort to please (her). And after explaining things time and again
she continues with her insecurity.
But she hides her insecurity, she masks it by complaining and complaining, by being demanding and seeing things in "black and white" ways...
Then after a long time he´s past the point where the straw breaks the camel back... so he gets in the "I don´t care anymore" and "let´s confront your insecurity right now! ...or never" mood.
Oh boy, I can see that this won´t be pretty!