THRUSH!!!
Sounds like a classic case of thrush, which is a variety of yeast infection.
http://www.kellymom.com/bf/concerns/thrush/thrush-resourc...
Symptom list form one of those resources:
"In mother:
intense nipple or breast pain that occurs from birth, lasts throughout the feeding, or is not improved with better latch-on and positioning
sudden onset of nipple pain after a period of pain-free nursing
cracked nipples
nipples that are itchy and/or burning and that may appear pink or red, shiny, or flaky and/or have a rash and tiny blisters; nipples may also appear normal
shooting pains in the breast during or after a feeding if the yeast has invaded the milk ducts
nipple or breast pain with correct use of an automatic electric breastpump
a vaginal yeast infection "
it also says "The baby may also be without visible symptoms"
I am currently nursing my 3rd child, but when I was nursing baby 32 I had a case of Thrush. bbay had no symptoms, and I did not have red or cracked nipples at all. BUt I did have the shooting pain, even with correct latch on.
I myselkf used gentian Violet, took garlic and enchinea, and did the vinegar rinses. It took about a week and 1/2 to clear up. If it had gone on longer I would've been willing to take an anti-fungal RX or Diflucan.
Good luck!
BTW - Sugar feeds yeast. So the comment about drinking too many Sprites really hit the nail on the head.