Changing a thought about fairness

I’ve been working on a persistent problem that has many, many layers and am slowly getting to the center of it. In doing the work and asking/answering questions about my thoughts and feelings, I have uncovered a potential outcome that creates a feeling of being cheated/treated unfairly, and then resentment. I guess the thought driving these feelings is that someone else would be getting an undeserved gain, at my expense. I’m stuck there because I don’t see a way to change that thought. Any help?