Hello, Clouds_and_Sun!
Nes and yo. No, I haven't felt exactly as you describe. Yes, I have felt painful frustration at my own inability to mobilize myself to productivity.

I struggled in a different set of circumstances. It grew obvious I was becoming less and less capable. My decision was to press forward despite the decline. In the end I "crashed." I have not recovered from that crash despite following doctors' guidance.

Sometimes I wonder about my decision to simply keep going. Had I stopped to regroup myself, would I have salvaged some ability to function at least on a low level in the normal world? I don't know.

The possible analogue to your situation is pressing forward now toward work. Either you will gain some traction in the world and maybe even a satisfying sense of mastery, or you will fail. The former would of course be better. The latter would be extremely painful but might provide the authorities with sufficient evidence of the intractability of your case.

Regardless, we'll stand with you.