There will be better advice coming, I am sure, but I wanted to offer my sympathy for what you are going through. It sounds horrific, but it also sounds like you may be able to recover, at least partially, or perhaps not progress.
While it may seem hard to believe, chronic pain sometimes has a way of becoming more bearable over time as you learn how to live with it. Also, there are many more medications than OxyContin that you may be able to tolerate.

Neurontin, or Gabapentin is the medicine I believe that you are trying to avoid. It is not always effective, but on the other hand some people are able to take it without experiencing side effects. I have not had a problem with it and it does control the zapping and burning to some degree. On the other hand it does nothing for the sharp or crushing pains. I take oxycodone for those, as needed.
If you need pain medicine to function then you need pain medicine. That is a medical necessity like antibiotics or anything else. Do not stigmatize yourself.

As for working and dealing with your condition, it is incredibly important that you treat yourself as well as possible and get as much rest as you are able. I am sure that will be difficult, but it will pay off. You are under enormous stress and it will affect your pain levels.

Your doctors should be bending over backwards to help you under the circumstances.