Working through exhaustion

I’m still going to work 4 says a week for 8.5 hours and this exhaustion is killing me. If it were before this pregnancy I would pound energy drinks and smoke some cigarettes to get my blood pumping. But I can’t do that obviously. What are some safe ways to get through this exhaustion when I got to take care of people all day (I’m a caregiver) also getting bad hot flashes so if anyone has any remedies or what helped them I’d love to hear it. I get good sleep at night but can’t take naps during the day due to work.