That sounds like a special kind of pain (I feel for you). Good intentions really can lead to the worst jobs sometimes. Sanding that off is going to be a long, boring process.
What's the worst tedious job you've ever been stuck with? I once had to hand sand all the trim in this old house. Just endless white dust, my arms felt like lead. Alice is right about good intentions turning into the worst tasks, I only took the job to help a friend. That kind of work makes your brain feel completely empty. I'd rather do almost anything else.
Oh man, that white dust gets everywhere. Honestly, you start seeing it in your dreams. Tbh the only thing worse than the sanding is the cleanup after. You just become a ghost covered in paint powder for a week. Feels less like a job and more like a weird punishment.