E.H. I wrote an article on Medium a few months ago, you may find intriguing on just this question you are asking,
If you have a bad thought, can you simply replace it with a good one? (And is that good enough? Will that be effective?
My answer to that is absolutely. But it can be a messy process. Three steps forward and one step back.
But living on the edge of creativity and possibility is exhilarating.
Link to my Medium article: