Hi & welcome to this forum fellow Aussie
When i read your post i zeroed in to the [ sugar a bit high ] as the cause of my PN was Prediabetes & low in B12, did you have a 3 -5 glucose tolerance test to come to that conclusion ? prediabetes is reversable and your nerves can regenerate once their in the right environment.

B12 helps repair damaged nerves, " Natures Own " have a b12 at 1000 mcg strength, its the only one in OZ that i know of that strength, blackmores are only have 100 mcg, not worth it, our b12 supplements are Cynocobalim which is still good there's nothing wrong with it but the prefered b12 is methylcobalamin which our american friends are lucky enough to be able to buy it off the shelves over there, but we can order in from overseas but works out about $70 a bottle, a bit steep for me, so i just stuck to Natures own 1000 mcg and shots of B12 Hydroxocobalamin of my quack.

Its best to buy some mega B as well, it helps the b12 work better, but best not to take it at the same time as the other b12 to work the best., i take my mega B at breakfast and the b12 any time during the day.

For info about b12 off a lovely lady thats helped us all so much and who knows a hell of a lot more than most doc's do, is at http://roseannster.googlepages.com/home.

I would also urge you to read the stickies in the front page up top, there's a lot of real good info, the more you know the better it is.
ps - the more info you can give us the better .
good luck
Brian