Try this experiment, whether for an hour, a day, a week or more. I think you will find it interesting.
Be mindful of your thoughts and take note of every time you are focusing on something you don’t like or want. When you catch yourself focusing on what you don’t like or want immediately replace it with what you do like or want. It is akin to brushing off a red hot cinder before it burns.
I think you’ll be surprised on how often you think of the things you don’t like and/or want. The good news is, being aware is the first step to changing the pattern.