You've already received some good advice. Another approach my DIL used with my grandson was to pull him in very close to her breast when he bit her so that it occluded his breathing at the same time telling him firmly "No biting!". He was forced to let go in order to breath and very quickly learned never to bite her breast again. This was even though he became a biting toddler who bit when he was happy, excited, mad, frustrated, etc. until he turned 3, but he never bit his mother's breast!
Kris R, IBCLC