L.C.
Hey T., I am part of a breastfeeding support group with lots of other moms that have gone through so many BF issues. Please join us. http://mommymilk.meetup.com/381/boards/
Once you apply to be a member, you will be approved shortly after. Also, the resource http://www.kellymom.com is awesome!
Your supply could be reduced for many reasons, your menstral cycle, change in diet, not drinking enough water, or drinking something else, like too much caffeine. Try drinking more water, eat more oatmeal, or drink motehrs milk tea.
He could also be teething. Give him something else to chew on, a cold rag, a teething ring, anything!
He may also be going through a growth spurt and trying to up your supply. So the situation is just temporary.
He may also be playing! So try to just offer the ninny when he is really hungry.
I would just pull him off the ninny when he gets rough and try again later. When my dd would bite me, I would yelp, it was a knee jurk reaction that often caused her to cry. We only did this a couple of times before she got the message, no biting!!