DO NOT stop nursing/pumping, that is the worst thing you can do!!!
I had the most extreme BF issues with my firstborn I have ever heard of but overcame them and nursed her to about 2 years. I learned a lot.
I'm not clear from your post if you have been nursing the past few weeks or you mean that you stopped and are now having problems. The very fist thing to do is call the La Leche League hotline and explain exactly what's happening.
24 hour Hotline: (877) 4 LA LECHE ###-###-####)
You may have quit nursing/pumping too suddenly and now have mastitis, clogged ducts and/or an abcess. All those problems are caused by not draining the breast. Below is info from a site I found with a google search but the same info is pretty easy to find anywhere:
How Will it Affect my Baby?
"Breast milk from an inflamed breast is perfectly safe for the baby, as the breast milk contains antibodies that protect your baby from diseases and infections.
Your infant may get fussy and refuse to drink milk from the inflamed breast. This is because your usually sweet breast milk has a salty taste due to your infection. If the breast is entirely refused, be sure to express it manually or with a breast pump."
Breast Abscess
"Mastitis can get very serious if not treated promptly, becoming a breast abscess. In extreme cases, untended mastitis can lead to hospitalization to drain the breast via incision. An abscess is a pus-filled boil under the skin. The abscess will remain even after treatment of mastitis, signaling the need for drainage. It is therefore important to consult your doctor on mastitis or plugged ducts, so that you can prevent a more serious condition."
If you are still nursing, continue, if you recently stopped start again. Call the hotline or a lactation consultant for breastfeeding information and see a Doctor for treatment of the infection.
In my experience most doctors know very little about BFing. This often does not prevent them from giving advice on the subject so please take it with a grain of salt and balance it with what a professional lactation consultant says.
Do not wait one more minute as this can get very serious and please let us know what happened. Good Luck!