When nerves are aggravated, they are stimulated by heat.

So try to use very lukewarm water during your shower, and see if that helps.

Also try a cold pack on the back of the neck for 20 minutes 2 or 3 times a day. If this is a nerve compression issue from the cervical spine, the cold will soothe it. Cold also stops viral replication if you have some virus like Herpes zoster activating in the neck. Place a thin towel or cloth between your skin and the ice pack. Don't overdo it -- only 20 minutes is all that is usually necessary. This also can cool down inflammation, if that is contributing to your sensations.

Pain that goes to the toe, may be lumbar. Here is a dermatome chart showing which nerves cause which symptoms:

http://www.google.com/imgres?imgurl=...w=1039&bih=653

When I had my right knee issues years ago (I dislocated it), the pain only went down that leg to my big toe! When the chiropractor did the adjustment, that pain stopped instantly! (I had it for weeks before I went there). It was very dramatic.

You may have several things happening at once. I'd get that B12 checked first off to see if you are low, to explain if this cause is making your nerves so sensitive. (as I explained in your other thread).