Is there anything that helps you sleep/stay asleep?

I’m currently 25 weeks pregnant & lately I’ve been having such a hard time sleeping & staying asleep. Like my body it’s starting to do it’s own thing. I end up taking a nap during the day because I start feeling bad physically, but then again I go another 12 hrs or so awake & even if I sleep 4 hrs I wake up in the middle of the night. It just sucks cause I have to wake up early for work & I already had a time I had to cancel cause I was feeling nauseous & dizzy from not sleeping well :/