The song lyrics address a destructive relationship or friendship, in which the protagonist tries to get their partner to be open and honest.
The protagonist feels hurt and wants their partner to be honest with them. They emphasize that this is the last chance and that they can't continue if he continues to shut himself off.
The text also includes a passage where the protagonist talks about their own problems and their dependence on drugs.
Overall, the song lyrics "Say What You Think" express the frustration and despair that can come with a relationship or friendship lacking communication and openness.
It's about the desire for understanding and support, but also the need to stand up for one's own well-being and leave toxic situations.