Oh geez that brings back memories of some nights with dd. I used to call it my 'demon mummy' moments because I could seriously flip out from sleep deprivation and frustration.

Be kind to yourself and try and see the warning signs. For me it's about lowering expectations in any given moment.

Taking a break outside and looking at the stars is a great way to calm you both down too (although tricky in summer time with daylight savings). Giving more responsibility to your dh would also help.