I have a small problem... I've been nursing almost 8 months :) and I have recently seen a huge…

I have a small problem... I've been nursing almost 8 months :) and I have recently seen a huge supply drop. I also have a baby that has been sleeping through the night for about 3 weeks :). How do I fix my supply issue. I've been drinking tons of water, gatoraid, taking fenugreek, blessed thistle, eating good for me and moisture rich foods. What else can I do? usually I get between 16 and 20oz pumping at work.