Sleep Deprivation is so hard 
If you can afford it go and get gel nails 💅
It will give you 3-4 weeks of lovely nails and a nice boost everything you look at them.
Wear rubber gloves/ get a nice handcream
Stern bit now
How much support do you get?
Absolutely not negotiable to not bath or shower daily -I used to bath in the evening and wash my hair, nice bubble bath, body cream and book.
Apply face cream after
Just having that hour to myself to look forward too kept me sane.
Your DH/P needs to be on board with this, no coming in or you getting out to the DC.
I would get some simple clothes that are comfortable and fit you now -you can always chuck on Vinted once you lose.
I called this my uniform-simple but stylish
Black Jersey wide legs and a wide roll neck jumper
Water is great, herbal tea instead of caffeine
Daily
Tinted moisturiser, cream blush, eyebrow pencil ( get them done when you go for gels if needed) mascara and lip gloss
Earrings
Outfit
5 mins tops
Diet
Look at healthy family meals
Chicken pasta
Garlic prawn pasta
Meatballs
Loads of veg/ salad on the side
Yogurt and berries or banana if you want some sweetness.
The main thing is to keep something back for yourself and not rush to put everyone else first.
I was an exhausted mum of 2 and one day observed what DH did.
No question he would shower daily, rest, do things he liked, take care of himself so I decided that it would be non negotiable for me too- got myself gel nails and a new book !
All the best 