Neilk,
Wow that is bad news to get out of the blue. You must be spinning. Literally.
I am so sorry to hear this. I don't qualify for disability but it has always given me a weird sense of comfort knowing that some of us are getting some assistance.
I am not familiar with the world of appeals so I can't give you any advice or anything on that. But I am familiar with having to be able to make it without nearly enough money coming in, been doing it for many years.
Try to get out of sympathetic Fight or Flight that's consuming you right now. I know it's really hard, especially now. But make that your goal for today.
Try not to let yourself stew about the situation. Again, really hard to do. But unless there is something you must do or can do today, try to put it on the shelf. And get into your parasympathetic nervous system.
That's where the healing chemicals are, that's where the ability to breathe is, that's where any peace of mind you might get hold of will come from.
It will perhaps keep your body from getting too pulled apart by this news, and maybe help you mentally (from head fog, or frightened thoughts) and emotionally (situations look even more bleak when we are frightened and depressed, solutions seem impossible.)
So, so sorry this is happening to you.
There will be a way out of this situation for you. I don't know what it is, wish I did. But, breathe, try to relax as much as you can, put it aside for now ... so when you come back to it later you will be better prepared for it.
Keep us posted, okay?