Moms who work 12+ hr shifts!

I was working 12 hr shifts in a slower paced environment prior to becoming pregnant. I started a new job recently in healthcare in a fast paced environment and the shifts are 12-13 hrs long. I do get adequate break times in between but I'm just curious.. how do you manage to not exhaust so easily? Pre pregnancy I would be able to manage keeping up no problem, but now it literally feels like I'm dragging my feet at times. Any tips? Also any shoes you recommend? I was a dansko wearer but now they feel like bricks! 😣