I know zero about Scaitica (never even heard about it until now) but, you're desperate so I thought I would ask if anything has changed in your bike setup. There are some nerves in the balls of your feet that could be getting compressed that cause numbing or burning feeling. Have you changed your setup at all? Or maybe your route has changed and add more climbing causing more pressure? Typically people will move their cleats back a couple mm, but if you can't, maybe you can try different insoles in your shoes (either thicker or thinner, depending on how your shoes fit). Also, maybe try different socks or having someone stretch out that area of your shoe. Sorry I couldn't help too much. Good luck, hope you can find something soon!