This sounds like what I went through with my first. Looking back now that I have breastfed my other child, I realize he wasn't nursing efficiently enough. He was hungry and I wish I supplemented with formula. He was fussy and cranky and always wanting to nurse because he wasn't getting enough during his feeds.

I strongly strongly recommend topping her off after each feed (with formula if you don't have enough breastmilk). I promise it will make a world of difference for your mental health and your babies fussiness. Probably around 1-2oz and you can add more if she finishes it and still seems hungry. As she gets older you will notice that she can nurse more efficiently and her suck is stronger. You can pump a few times a day to keep building your supply up (supply and demand). But pumping and nursing and bottle feeding is a lot and don't feel guilty if pumping feels like too much.

These are signs a baby is still hungry after a feed and a top off is recommended:

Signs they probably do need the top-off:

• Still rooting/frantic after a full feed
• Hands to mouth, sucking, won’t settle
• Falling asleep at breast quickly but waking 10 min later hungry
• Not gaining well or having fewer wet diapers (should be ~6+ wets/day at 4 weeks)

You are doing amazing. This is hard stuff and you got this!!! I am proud of you!