Hi Jasonius and welcome to the forum,
Your sugar levels above normal range could indicate Prediabete's, which a lot of doctors ignore but it can cause the same symptoms as a full blown diabetic, burning feet is one of the symptoms and should NOT be ignored.
Excessive insulin levels can be very dangerous and that should be evaluated properly, it can lead to real problems like Diabetes amongst others and seeing you felt a differance in temp feeling with his neuro test, i am surprised that he never ordered Quanitive Sensory testing, your burning feet is a typical sign of peripheral small fibre damage to the extremities.
this explains QS testing - http://millercenter.uchicago.edu/lea...nt/index.shtml
I would have a good talk to my GP about those Insulin levels and definatley find another neuro that is a real expert in PN.
good luck,
Brian