Long story short - our LO is 18 days old and just started becoming fussy about 2 days ago. Today we reached a new low - he's been screaming any time he's awake and won't breastfeed (latches on but falls asleep immediately, then wakes up again rooting around and screaming, and does that over and over again). He was successfully breastfeeding before today. Tonight has been the worst - he woke up from a nap screaming so hard that he can't even focus on latching on, so still no breastfeeding. He's hungry and screaming. Earlier today we had to supplement with pumped milk for the first time, which I'd like to avoid again if possible. We are just about at our wit's end and it's only been one day of this.

Any tips on getting a fussy, screaming baby calm enough to breastfeed?