My Job Is Demanding I Do Things I’m Not Physically Able To Do Until I Get A Doctors Note.

So I got a new job and the duties that were listed on the job posting were mainly administrative work. I happily signed up for it because last year I broke my ulnar bone and smashed my radial head so I had plates and screws and a replacement and I can’t fully straighten my arm and there is always pain when picking up something over 20lbs. so I need more of an office job. My new job is now demanding I do community work because they are short staffed. I told him that’s fine. I’m always happy to work, always happy to jump in so if they needed me to drive the smaller van to drive people around or take people that were capable of walking on their own, I’d be more than happy to do that in addition to my responsibilities, even though it’s making me have to work at night to catch up on my administrative duties. Last week they kept putting me with people who were wheelchair bound and needed to be picked up for changing and also was told I have to drive a much larger van. I told them that my only concern was that I can’t really pick up somebody that’s 85 pounds due to my arm. I also told him I didn’t feel comfortable driving such a large van without being trained, but they didn’t care. They also put me with one other person and three wheelchair bound people which meant me trying to steer two wheelchairs. That in addition to having to pick the other person up to change them because the other person was refusing to do, it made me hurt my arm and now I’m experiencing weakness and pins and needles. I have called my doctors office numerous times for a note but they insisting that I have to come in and I can’t get an appointment till next Friday. I’m on the schedule again next week to do these tasks and I just can’t do them and my job just doesn’t seem to care. I just don’t know what to do right now. I can’t afford to quit and I can’t afford to lose my job. Again, I’m more than happy to help out in anyway I can where I’m physically able to. Location: Pennsylvania