Note - Peppermint is used to dry up milk supply - nursing mothers should avoid peppermint!
I have never pumped that much, and I found that my daughter actually reverse cycled after the first few weeks (I had enough in the freezer to get her though until this happened). So she ate most of her calories at night and only had 9 ounces most days. You can also try adding a morning pumping after her first nursing or before she wakes up.
What helped me:
*Relax if you can while you pump, drink something warm and soothing, eat, look at pictures of your daughter, hold one of her blankies that smells like her, etc.
*Drink plenty of water and eat well.
*Figure out how to get a good let down with your pump. For me that meant letting the letdown feature run for the entire 2 minutes (PIS Advanced) and sometimes even restarting it to use the letdown feature again (PM me if you want more detail).
*Pump longer - I usually get a 2nd letdown if I pump for more than 20 minutes, so I usually go until after that 2nd letdown).
*Do breast compressions when the milk flow slows down.
*"Power pump* every few days. Pump normally, stop, and then pump another 10 minutes or so 15 minutes after the first session. It really does help (learned that from a momma who exclusively pumped for a year.)
Good luck! It all really does work itself out.