I found regular exercise helped me stay calm. A crappy overnight after effect was reduced by a good workout. Early mornings went from annoying to calming long walks. Even 2am screaming matches became walks up and down the street. Tho I never lost any weight as I ate my frustration in chocolate.
But honestly, my kids were crappy sleepers in patches but not always. And they've always been great day nappers so that's how I continued to function on broken sleep overnight. I'm rambling now but I believe that once we accept that our kids are crappy sleepers for whatever reason then there is less anxiety all around. When dd1 was waking every 40min from 6-9mths it was a freakish nightmare. But it passed as I bed shared thru this. She had horrible separation anxiety and even now as a 5yo she will bed share when Dh is home as she misses him. When dd1 went thru the 18mth regression and flat out refused to go to sleep I almost lost it. I had to walk her in the pram every day for naps and bedtime. It sucked as it lasted 4-5mths and I went from 7mths pregnant and then with a newborn doing this malarkey. The amount of ppl who told me to drop a nap where endless but we persevered as we knew she needed that nap. Then it just miraculously passed. Now at 5yo she still naps 1.5-3hrs every day.
Dd2 was a clockwork 3hrly feeder till 9mths. Nothing could make her drop those overnight feeds. It was getting to me and I was part of that sleep vents thread for it. I had a toddler and was back at work so couldn't nap as much. But that passed too. Dd2 is currently 3yo and going thru a very needy phase. So whilst she goes down easily in her own bed she moves into our bed once she wakes. Meh. It won't last forever. Plus it's not worth the electricity bill to run separate heaters in the bedrooms.
I think I managed with acceptance, naps and bedsharing.
It will be interesting in October when I have a newborn, 3&5yo with DH away.