I meant my breast not breastfeeding, am in my fifth week.
Over time, the tenderness does reduce. It could be how your baby is latching. My son sucked in his bottom lip and I had to always pull it out for the first weeks, otherwise it would kill!
Once you get a good rhythm going, you won't even notice your breasts filling up anymore. Your body will automatically know how much your baby needs and it will be there for them.