I am sorry and can relate. When you went to see the pain doctor did he suggest anything? For me the pain doctor worked better with pain and inflammation then the neuro. The neuro was more about finding dx and testing.
Some symptoms go hand in hand and stem from the condition so if you get to a better place with the rsd it may help with the swelling. I may be making no sense. An ex is people who have done ketamine it helps their pain but also you see if they had sores they go away. So I am wondering if the swelling is part of the rsd if a treatment that helps that will bring down inflammation.
When you see the pain doctor since you at one time had results with prednisone I wonder about another med to help with inflammation?
Hang in there and hope the apt goes better today