3 days PP

Hi, I’m brand new to all of this. I’m 3days PP and my supply is finally starting to come in. My baby doesn’t latch well and needed formula bc of GD after being born at 37+3. I’m still trying to nurse but for the most part I pump. I am pumping every 3hrs and getting about 20-25ml per session. My boobs are killing me though. They are so hard and lumpy even after pumping for 20min. I use a warm wet wash cloth and massage before I pump and they still hurt. I pump until there are no more drops so I assume I am emptying them but they still feel full. Is that normal? Also, how much should my supply increase every day? I really want to get her off formula if I can.

Any advice is helpful!!

Thanks so much!!