When I was hypothyroid my glucose was always low. Some fastings like 70. When I had my treatment with levothyroxine started my fastings went up to 90. Consistently low blood sugars may indicate a reactive hypoglycemia, which may be starving your nerves when it occurs. When glucose is low, the mitochondria cannot produce energy. A supplement called acetyl carnitine can help encourage fatty acids to be substituted so that the cells can function more normally. Carnitine is normally made in our bodies, but this synthesis may become damaged and fail.

Yes, unfortunately, the Levaquin is a possibility. On that link I gave you, there is a link to Dr. Jay Cohen MD's website where he has suggestions to help overcome fluoroquinolone toxicity.

The mechanism by which these drugs affect tendons is not clearly understood yet. But as far as the nerves go, I suspect a mitochondrial damage of some kind. I have several links in that thread to other places that give more details. Some people believe this damage is permanent, but Dr. Cohen holds out the hope that some supplements may help.

The A1C is an average reading over time that shows spikes in blood sugar that regular testing misses. In many ways it is more useful than glucose readings. Aberrations in blood glucose may be "hidden" for many years, before showing up in standard isolated glucose testing. Some doctors believe these aberrations start the process of diabetic neuropathy.