Work and pregnancy accommodations

I recently got off leave from Amazon because I was given accommodations from my doctor that they declined to accommodate. They put me on short term disability that is now exhausted. Since going back they have tried to give me easier jobs but the prolonged standing is killing me and painful, I'm currently 34 weeks. The accommodations requested by my doctor are no lifting more than 25 lbs, a 10-15 minute break for every 4 hours and no prolonged standing. I have 10 hour shifts as a picker/packer and so I'm on my feet the entire time. And by the end of shift, I'm very slow and limping because of my sciatica, hip and lower back pain. I push myself because I don't want to be to slow and want to try and meet the expectations of the warehouse so I won't be fired. I'm terrified I'll be fired. I had talked to the nurse practioner at my doctor's about a leave as accommodation. But she said since I have nothing medically wrong such as preterm labor, etc that I can still be working. I had said nothing about the prolonged standing being an issue though. Am I being overdramatic about being on my feet that long or should I say something?