Exactly how high is your B6?

High B6 neuropathy is very rare.

I have to caution you about those heating treatments.

My chiropractor explained to me that 10min tops for any heat treatments. Heat activates nerves and makes nerve pain worse. Heat will have a seemingly irritant effect and distract from the deeper pain, which will mount the more you use heat, and the pain will last all day then.

There is not very much muscle in the neck. I'd stop the heat treatments and see what happens. Large muscles can absorb some heat, but in the neck? It is mostly nerves and tendons there.

There is a form of neuropathy called RSD (CRPS) and it responds to heat, and does not like cold. So you should investigate RSD as a possible chronic pain cause.
http://neurotalk.psychcentral.com/forum21.html

You should see results with the Morton's lotion within days.
If you continue heat however, there may not be much response.

There is B6 in your food if you eat fortified things like cereal and pasta and bread. Most meat protein contains B6.

The actual B6 papers, that were at one time hitting PubMed were from massive use of 500mg or more a day for years. This at one time was a treatment for PMS in women. It is no longer used. The only current high B6ers I've seen were kids in athletics in school where coaches were pushing it. I met a woman whose daughter was injured in a freak accident ...she was in the backseat of a car which ran over a piece of metal in the road, which flew up under the car and pierced her thru the torso! It luckily missed vital organs, but her muscles were very damaged and her mother discussed it with me. Her swimming coach had her on massive doses of B6! I put a stop to that quickly!

B6 in most supplements and food is pyridoxine and that is inactive. It is activated in the liver by pyridoxal kinase to P5P. If you are low in B2 (riboflavin), then you are not activating what you eat. B2 is in the cofactor enzyme to activate B6. This may hang around and therefore test high.
Most people who test out of range in blood work, have serum tests and these reflect B6 not in tissues. When looking at energy drink content (5 hr energy) or food labels, and removing pyridoxine intake their subsequent tests come down.
Keep in mind that the ranges were determined before food fortification and with the subject not using supplements. Use of any supplement being consumed and not stopped when tested may result in a false elevated reading.

So stop that heat treatment for a while...and see what happens.
Your B12 is adequate, so you don't need further supplements there. If you did not stop your B12 when you were tested, your result may be falsely elevated too.