I destroy negative thoughts by thinking positive ones instead

You do not argue a song out of your head. Try instructing yourself to stop hearing it and you get another eight bars. What works is playing something else. The thing gets displaced rather than defeated.

Arguing with a bad thought keeps it in the room and hands it a second turn to speak. Replacement is quieter and much less satisfying, because there is no moment of winning.

That is the trade. You can have the fight, or you can have the afternoon back. It is rarely possible to have both.