I need some help in ways to produce more breast milk. When I first started pumping I was getting 5-6…

I need some help in ways to produce more breast milk. When I first started pumping I was getting 5-6 oz out of each breast each time. But lately I can barely get no more than 3 or 4 oz per breast. I was buying these lactation pills called Motherlove :more milk plus (picture in the comments) and they really help, but they run out fast & I just don't have the money to buy a 26 dollar bottle of pills every 3 to 4 weeks!! I drink plenty of water and milk, but are there any other ways to help increase my milk production. I'm going back to work soon and I wanna be able to have enough milk to feed my son during the day but also to start storing in the freezer.