Burnout/imposter syndrome while leading

SWE with 6 YOE. I’ve been leading a “lift and shift” migration for a while now. The domain is messy, poorly understood, and has a lot of legacy behavior and data issues. Product involvement has been limited, so it’s mostly me driving decisions about system behavior and deliverable sequencing. The scope keeps changing wildly and we keep having to research potential features that never get picked up.

Since it was first assigned to me, I’ve felt a persistent level of anxiety about it. I procrastinate around designs, specs, and even writing tickets. I feel like I don’t make enough progress during the week, then end up stressing about it outside of work. I keep hoping the project will get cancelled so I can stop leading and go back to working on something else.

I’m struggling to figure out how to work through burnout and imposter syndrome while still being responsible for a long-running, ambiguous project. Has anyone been through something similar? If so, what helped you get unstuck or make it more sustainable?