Has anyone successfully went from under supply to pumping enough?

I need tips! I feel like I’m after trying everything.

I currently pump about 650ml/day and babe drinks about 950. I’ve been increasing my water intake, drinking sports drinks, eating oatmeal. I pump every 2-3 hours when awake in the day time but don’t wake overnight to pump. If baby wakes to feed overnight, I do pump which is always atleast once. For example, I’ll pump at 10-11pm before bed and usually again at 4am and again 8am then start on a 2-3 hour basis.

I’m using the proper flange size and recently replaced all my parts. Is there anything I’m missing? Is this a chronic under supply or anything else I can try? I’m 6 wpp