Y.W.
Congratulations on the new baby!! When mine were sore, I had an infection. My daughter had thrush. I was told to treat it with an antifungal foot cream. beleive it or not, the dr said it was OK to still nurse with the cream on.
If that is not your problem, you might wantto get another pump. I tried one that hurt so bad, I had to stop using it and go back to my hand pump.