Slight update: I was able to convince my manager to move me into a different department, & the work I started doing today certainly felt a lot better for everything except the last 2 hours of it. I'm doing stretches/breaks constantly & taking lots of precautions, but it's still hard on my body... :(
I'm literally slowly developing right hand/arm muscle weakness & pain, and I have no way out of continuing to work the job that's causing it to be this bad in the first place. Can't even guarantee I'll see a doctor this week :( Please let me survive this week, let alone this month...