Maybe you can try to drink soya bean milk, now I'll drink a glass of soya bean milk everyday (buy at Manning $8). Very convenience & very work for me, to keep the quantity... now my daughter is 14 months old, I can keep enough breastmilk for my daughter.
7.00 am - direct BF
11.30 am - pump 7 oz in office
4.30 pm - pump 7 oz in office
8.00 pm - direct BF
12.30 am - direct BF