Been there OP, it's awful.
Your OH needs to get up with kids and give you a few hours sleep in the morning before he starts work.
Fuck the cleaning.
Make life as easy as possible for yourself for a while. E.g. use paper plates so no washing up, serve same meal 4 x a week to kids, get ready meals for you and DH, don't worry about laundry piles, hide clutter in a cupboard until a later date. Lower your standards. It's not forever.
Get OH to take kids out on weekend so you can have a few hours to yourself. Sleep, have a bath, whatever makes you feel good.
Go to bed with the kids at least 3 times a week. Get OH to make his own dinner.
Cosleep.
Rant and fucking rave about everything to a trusted non judgemental friend who is a good listener. Don't have one? You're welcome to PM me.
You need to get back to a place where you can feel like you, and fill your cup.
You're a great mum, just knackered and at the end of your tether. If you are struggling with what I'm suggesting, ask yourself if you had to choose between not losing your shit at your kids and a clean house, what would you choose?