At this point, I switch to my breast pump until the nerve endings have recovered. This time it only happened on one side so I'll let baby nurse for 20 minutes on the other side and then pump. At this time she's getting enough with one side. I only let her nurse when she's calm and try to start nursing about 15-20 minutes before she realizes she's hungry. This requires notes on every feeding and alarms set so I can stay on top of her schedule.
It usually takes about 2 days to recover and then we can go back to a regular feeding schedule. Meanwhile it's nice to have started a small stockpile of milk!
The real point of this post is to not give up. This is my 4th baby and I've had this happen with every one. Once we get passed the 3 week mark its like the body just gives in and resigns itself to the abuse. So don't give up at week 3; after this point it should get easier.