low supply question from a lurker

sweetbabyrahe

I don't normally frequent this board, but I am looking for some help. I have a full time working mom breastfeeding once in morning and once in evening. I pump 3x/day at work. Within the last 2-3 weeks, I have had a decrease in supply and am quickly burning through my freezer stash. I tried supplementing with one formula bottle for the past three days, and my son refuses to drink any of it. I have tried regular Enfamil and Similac Advance and given it to him by itself or mixed with breast milk. He won't even try it. I am frustratred because we are getting so close to a year.

 First of all, does anyone have any good suggestions to increase supply?

Any suggestions for a good formula to try? Anyone experience the same thing and gotten through it?