Have you noticed that whenever you have a song stuck in your head, the harder you try to make it leave, the more stuck it seems to get?
It's like a Chinese finger trap.
The same is true with thoughts you don't like.
You don't have to fight them.
You can just observe them.
When you realise that you are not your thoughts you don't feel the need to justify yourself to them.
That's a much easier way to live.