Nipple feeding causes pain and soreness at the nipple. Can apply breastmilk or coconut oil to the nipples to decrease the soreness of nipple. Can use nipple shield (silicone) so child can take feeds through it so you don't get the pain. More importantly as child is 9 months old, you can use wooden teethers or steel spoon or middle hard and long piece of carrot for child to chew so he doesn't bite on your nipples. As there is a tendency to chew at things due to mouthing and teething.