B.W.
An 8 month old doesn't wean himself, if he stopped nursing, its a nursing strike. I would pump your breasts, do NOT give a bottle, and keep offering the breast. H ewill come back. At 8 months old, its prime age for a nursing strike. HE's more interested in the world around him, and wants to be up doing stuff. If you give him a bottle, it will only exacerbate the problem, because he can roll around, look around, etc with a bottle in his mouth.
Again, 8 month olds don't wean themselves, its a nursing strike. Take him into a quiet darkened room to nurse. Nurse him when he is tired, when he is just waking up, etc. He will come back.
Stopping abruptly is not good for your body. You are susceptable to clogged ducts, mastitis, and infection because your body is suddenly stuck with all this milk that it was once using. Stopping suddenly is the worst thing you can do.
Here is some info on nursing strikes. http://www.kellymom.com/bf/concerns/baby/back-to-breast.html
http://www.kellymom.com/bf/weaning/babyselfwean.html
I would encourage you to keep offering. Nursing strikes can last anywhre from a few hours to a week or two... but he WILL come back, just keep offering, don't give bottles, and make sure that where you nurse is quiet, darkened, and nothing is distracting him. Waiting until he is s leepy, or just woke up, or crying/hurt, etc will help. I hope you read the links above, it will explain a little more, and also help explain that 8 month olds don't wean themselves. Good luck!