Drink, Drink, Drink (water that is). Making sure I am really hydrated helps keep my supply from going down.
A lot of people have had good results with power pumping also ...
http://www.justmommies.com/forums/f1...ping-info.html (Power pumping info)
I don't know how often you pump during the day, but trying adding another pump session in too .... or at night. I know I gave up a lot of milk when I gave up my 2 AM pumping session around 7 months, but I really needed the sleep! If you need the milk more though, those night time pumping sessions were great for me. Might not be as easy adding one back in, but might help after a bit.
Good luck!! You might also try a different formula if you really need to get him eating something. He may like a different type better. Talk to your pedi about it. They often have samples they can give you so that you don't buy a whole can of something only to find out your baby won't drink it.