4 yrs post I have neuralgia on my left side w/ lump there and running a fever. Left areola is turning white. What could this be?

It is understandable that you are concerned, having various symptoms and no definitive diagnosis from your local physician.  Your plastic surgeon should be able to evaluate your post-op breast reduction situation and advise you on issues related to the breast surgery, including the pale color of your areola.  The other symptoms need evaluation by a primary care physician.  If the current answers aren't satisfactory, then you may request referral for another opinion, perhaps in another city with a larger medical community.  Best Wishes