Hi, mine was caused through prediabetes and low B12, the best thing i found was to get my sugars back down to as close to normal as possible and keep them there so your nerves can eventualy heal in time, watch out for lows as well as they can damage the nerves.

The supplemements i found helpfull besides B12 were
R - lipoic acid [100 mg daily] can lower sugars so keep checking your meter.

Gamma-linolenic acid (GLA) is an n-6 (omega-6) polyunsaturated fatty acid commonly contained in Evening Primrose Oil (EPO) and Borage Oil (BO). EPO typically contains more GLA than BO. Depending on the method of extraction from the plants, EPO can contain varying amounts of GLA. Buy a brand of EPO that contains at least 10% GLA. For example, choose a 1300mg EPO tablet that contains at least 130mg of GLA.

You may find it hard to get B12 methylcobalamin in Melbourne, chemists usualy only stock b12 cynocobalamin which isn't the active form like methyl' some compound pharmacies sell methyl but want a small fortune for it, i used to get all my supplements from the US from an online store called iherb, very inexpensive that way, takes about a week to get them over here in OZ.

Best of luck to you.
Brian