This is a song about the inevitability of breaking up, when one has such feelings of worthlessness.
He feels worthless, inferior. And even if the relationship has lasted a long time, and there have been happy moments (which are seen only as a cover - clouds of smoke), he feels in himself that there is no reason for her to love him. That he will always be alone. He is unloved, unlovable.
This is a song about the inevitability of breaking up, when one has such feelings of worthlessness.
He feels worthless, inferior. And even if the relationship has lasted a long time, and there have been happy moments (which are seen only as a cover - clouds of smoke), he feels in himself that there is no reason for her to love him. That he will always be alone. He is unloved, unlovable.