I had a baby 4 days ago and my breast got really big and hard, how can i stop it being sore?

Ice and Bind Them: You are probably experiencing breast engorgement. This means the breasts are full of milk. Put ice or cold packs on your breasts and wear a tight sports bra or bind your breasts with an ace bandage. Cold and pressure will reduce milk production, if you are nursing, do this right after feeding, then put a warm wet washcloth on your breasts just before the next feeding. Do not pump or express milk.