Sorry Rebecca, I can't remember how old your lo is? When I work the night shift, my ds drinks 8-9oz soy milk before bed, but he is 18mo. How did he sleep that night? Was he satisfied for as long as he normally was with bf?
If you're concerned about his intake, could you offer him some during the day with meals and/or snacks? Any added to solids counts too.
Re: the pain, you can pump off some excess milk (just enough to ease discomfort) and use cold compresses or cabbage leaves for some relief. Feel free to start a thread on bfing about that too. Plenty of moms have been there and you're sure to get loads of tips