I need some help from all of you that pump successfully! Some background: LO is 4.5 months old and has been EBF since birth. I recently returned to work and am meeting his needs fine, but am only very slowly building a freezer stash. I have been working very hard to increase my supply using the great advice in previous threads, but I consistently get between 21-28 ounces per day. The variance mostly comes from how much i get in my first session (which depends on how many hours LO slept- which varies greatly! I nurse him in the MOTN so I can't track ounces).

Things I have done:
-Take fenugreek and blessed thistle 3x per day
-drink mother's milk tea 3x per day
-eat, a LOT
-drink water, a LOT
-eat oatmeal (instant) with 2 tbs flaxseed every AM
-pump 7-8x a day in addition to nursing 3x a day (20 minutes 3x, 10-15 minutes 3-4x at work). Always pump through a second let down.
-drink a hoppy beer 2-3x a week
ETA: Things I forgot to mention
-my first pump session is 5am, after shower
-i pump more often in the AM when my supply is much higher

Things I am thinking I'm doing wrong (not sure)
-i need to eat more protein
-i need to get away from instant oatmeal and get real oats
-LO is not sleeping well or consistently

Is increasing my supply at this point hopeless? I would really like to have more than a couple feedings stashed away. I'd like to be able to consistently pump 30-35oz a day, which isn't THAT much more. what else can I do?!?!?!?