I am very very sorry to hear what you are going through. From your descriptions it does sound like there is a strong possibility it is RSD which I am very sorry to hear.

In terms of getting the doctor to write you out of work...this can be tricky. Does your employer have short term disability paperwork? If so I would get a copy of that and make an appointment with your doctor to follow up on your concerns and to go over the short term disability paperwork. It sometimes help if the doctor is hesitent to bring a job description with you and explain to him WHY you can't do your job in your condition. If your employer doesn't have any specific paperwork or a job description written up then I would take the time to write/type up (or have someone else do it for you) what your job involves and explain to the doctor why you can't do these things and need to be off work until you get all this straightened out.

Also, I want to express my concern about the immobilization of your arm. Immobilization is BAD NEWS for RSD. THe more you immobilize and protect the limb, the worse the pain gets. You need to try and move your arm as much as possible...even if it's just a little. I know the pain will be excruciating but it is absolutely essential if you want to keep this from getting worse. I know when I first got RSD and they were trying to figure out what was wrong they had me immobilizing and initially I thought that made things better...but over time they just got worse and worse and worse. No immobilizing and no ice. Physical therapy was essential to get me functioning again and to stop the downward spiral where every day it was worse than the day before and I had more symptoms. And, from your story, it sounds like this is what is happening to you because it has gotten worse over time as you've had it immobilized.

I am very sorry to hear what you are going through. You definitely need to get this addressed as soon as possible and treat it aggressively. A neurologist and a pain management doctor are probably the ones you want to see as soon as you can to get a diagnosis and get started on treatment.