Changed diet - reduced sugar drastically, incl alcohol, desserts. Diet more plant-based, more protein, much less carbs. Added exercise, minimum of 5000 steps per day which seems to reduce nocturnal pain and irritation. Apart from taking metformin I am taking a number of supplements which promised reduction of PN or regeneration of nerve endings: Acetyl-L-Carnitine, vitamin B. Main problems were pain and irritation in the feet, but not excessive, nothing that Naproxen could not hide. Now all/most problems have disappeared, as long as I keep up exercise.