Thanks for your question! I had been holding out hope for "normal" in the spring and even began to practice in the driveway and the very lightly-trafficked road we live on. The problem was simple: my feet would vary from barely there to totally numb, like a switch blinking on and off.
I couldn't find the brake pedal, and even then the subtle pressure on the accelerator and brake was impossible.
Then I discovered the sheer joy of reverse. Looking over my shoulder, my right foot would slip off the brake and onto the accelerator -- hard. The neurologist said the nerve damage may be permanent and so it was time to get out of the driver's seat.
My venerable 2004 Corolla had depreciated to nearly nothing but was in excellent condition and I had thought I'd get maybe another 10-12 years out of it with the now-low mileage travel. My granddaughter was in desperate need, so I gave it to her with the counsel to take good care of it and it would serve her well.
She totaled it two months later on an icy patch of road and the entire saga came to a melancholy end.
I had thought about those hand control modifications but at my age and with the nature of day-to-day activities (very avid gardener), I decided it wasn't worth it.
I don't envy your constant discomfort and the frustration that goes with it; my particular brand of PN often means I can lose feet feeling at any time, often in mid-step. If lucky, I won't fall but do stagger like a drunk. Learning to adapt has been an interesting challenge.
Best wishes in finding a solution that works for you!
I gave up driving for the same reasons you did. Now my wife does all our driving.