“I should” to “I don’t want to”

I’m working with “should thoughts.” I’m working to transition to “I want to” or “this is available to me to do.”

But I discovered that “I should” was a lie to cover up “I really hate this” or “I don’t want to do this.”

I’m curious how to relate to these things in my job.

C- boss requires XYZ project or tasks
T- I don’t want to do this

But at the same time, I do like my job and want to keep my job. My boss isn’t willing to take that particular project off my plate.

How do I start relating to or working with the model on this? I have a strong preference against this kind of project, while at the same time valuing my job over all.