1. You can use pain relievers like Paracetamol

2. You need to let the wound heal.You may want to express the milk and allow the wounds to heal on one and as soon as that is done resume breastfeeding on the healed side

Sore and cracked nipples occur when your baby's mouth is not properly attached to the breast. When breastfeeding, your baby's mouth should cover not just the nipple but the nipple and the areola that is the dark area above the nipple, that way your baby can properly latch and there wouldn't be room for cracked and sour nipples.