Ferritin is stored iron. It is complexed with a protein.
In order to see if you are iron deficient, you'd need to see what your other blood work says. People can be okay with iron, but using up stores, so the ferritin gets low.

Problems with protein can contribute to this. Iron and protein need stomach acid to be absorbed well. Nexium would reduce that stomach acid. Women who still have periods never get good ferritin levels sometimes because they are always losing the iron. So not much get stored. Some pre-menopausal women have heavy periods too, and that doesn't help.

Your B6 reading is still in the normal range...and probably reflects your vitamin intake. The ranges were not made from people using vitamins.

Some of those symptoms can reflect thyroid issues too...so I hope that was checked as well?

It is hard to say what is going on. Some drugs cause these sensations. Simple treatment with antibiotics can do it. (Cipro, Levaquin, Avelox, Flagyl). Vaccines, virus infections, toxins, all these can cause nerve sensations like you describe.