Well i can relate on multiple levels. Except for I have been able to have some help with meds. I'm so sorry you have not.
I as well feel notably better on prednisone and have wondered at the specifics of that. i have an ongoing interest in vascular permeability kuz it sure seems to be a key in what's going on, so that article is of interest to me. Specifically I suspect that vascular inflammation due to autoimmune hypersensitivity causing vascular permeability may be key to so very many symptoms categorized under dysautonomia. Could it be that the same underlying autoimmune hypersensitivity is effecting both neurology causing dis-regulation AND vascular inflammatory problems compounding the issue? And in my case I suspect that the immune hypersensitivity is not an autoimmune disorder per say, but a result of the many diet and environmental factors that are a reality in today's world... Those are my musings. Would love to hear more of your thoughts on that if they are along the lines of your reality.
Aaaaanyway, I digress. I don't know if it would be helpful, but I thought I'd mention this: I have chronic sinus problems. I think some is infections, and some likely vascular permeability touched on above... But about 8 months ago my ENT started me on Azelastine. I feel like I do when I'm on Prednisone! Without the negative agitation, etc. It's like the pressure, brain fog, out of it etc is just improved. Maybe i'm just on a good run on the health front, that happens sometimes, but I suspect the Azelastine has a big part in it. I could take Fluticasone nasal spray because it messed with my heart rhythm.... but this seems to be working for me. In the US it's over the counter, so I just thought I'd throw it out there in case it made a difference for you. I'm on a cocktail of other meds that have been of great help to me, this one seemed related to whatever happens in my body when I'm on prednisone.
Best of luck, GardenGal