Biting during breastfeeding!

Me and my son have had a wonderful BF experience...until now. He is almost 6 months and just popped his two bottom teeth. But not my nipples are so sore and he bites me! It hurts! It literally makes me afraid to nurse him. I'm on edge when he eats and my nipples are always sore. I don't remember my first son biting so much. Or maybe he just didn't get his teeth so soon. He eats 1-2 meals of baby food, rice cereal and breast milk a day. He won't drink from a bottle so pumping and giving it to him through a bottle won't work. Any advice?