Sleep deprivation is no joke
We're on night 4 with our daughter and I genuinely don't know what day it is. My wife and I are trying to trade off but honestly neither of us is getting more than an hour straight. People keep saying it gets easier but right now I can barely function at work. When does this part end?
Night 4 is still survival mode. You're going to feel like a zombie for the next few weeks but it does get better. Both of you need to sleep in shifts if you can - don't try to power through together.