So exhausted at work! How do we manage??

Sara • Linewife and Mom of two girls! ❤
I work in housekeeping at a nursing home-like community, on my feet constantly, vacuuming, scrubbing, going up and down stairs all day long. I am to the point where I'm hardly getting any sleep at night. How do I manage to continue this work, till the baby comes, while being so worn out all the time? 
I'm at 25 weeks, so I know it's only going to get worse (all the ladies at work keep kindly reminding me of that) 
What kind of work do you girls do, and how are you handling the exhaustion and aches and pains?