Capsicum pepper can reduce nerve pain and improve circulation due to its capsaicin content. Creams containing capsicum used to be available on the NHS years ago but I don't know if they still are.
Tiger Balm contains capsicum and that might be worth a try. You'll find it in Health Food Stores and Pharmacies.
Fibromyalgia is quite a complex condition. You'll find a lot more advice on our website including the effects of diet, exercise and recommendations to help mood and sleep, all of which can help your symptoms greatly.