solids killing supply?

brideinsummer04

As I've been increasing the amount of solids ds gets my supply has been decreasing even when I'm pumping at work. Shouldn't it just decrease when I'm home? How much of a decrease is normal? I'm losing a whole ounce at each pumping session. I had low supply in beginning and so am already taking fenugreek, eating a lot including protein and oatmeal, drinking lots of water, feeding on demand when home, etc.