I suffered peripheral neuropathy in my feet at prediabetic levels, it was only when fully diabetic and eating low carb that things resolved. had i known when prediabetic i could have done something then. Reduce your carb intake, this will reduce your blood sugars, probably taking you out of prediabetes, and should help the pain. Eating low carb you will realise that those little aches and pains you put down to aging, weren't.
Evening primrose oil is touted as anti inflammatory, probably why advised, guess what low carb is even more anti inflammatory.