I've worked nights for 5+ years now and the only tips I can give you are;
1. Get restful sleep. If you sleep 8 hours it means fuck all if you're waking up every 45 minutes. You need to find out how to get sustained, deep sleep. This usually means making sure you're legitimately tired (no caffeine a few hours before bed), relaxed, and have a clear mind. Most people I know even now struggle to get good sleep (I'm no exception, but that's for personal reasons).
2. Exercise. If you're on your feet a lot at your job you might think you're okay--WRONG. Walking definitely can be classified as exercise but you need to be exercising multiple muscle groups. The easiest way to do this is to do a light bodyweight exercise in the morning when you get home, and/or at night when you wake up. Push-ups are a miracle exercise because they work a ridiculous amount of muscles considering how basic they are, crunches (and variations of them) can be decent, pull-ups are another stupidly good exercise, if you have access to weights obviously that opens up with you can do, but even just doing some stretching and going for a light 30 minute jog can make a world of difference.
3. Diet. If there's one thing I've learned over the last 5 years, it's that working nights encourages you to eat garbage. With most jobs, if you are running late or forget to pack a lunch, you have options. With nights, you're basically stuck with vending machines and fast food--both of which basically rot your insides. Making your lunches is an easy way to boost how you feel--Salads with a light amount of dressing are good, sandwiches are easy and assuming you get good ingredients can be decent, soups, rice, pasta is alright but really carb heavy--basically avoid processed and sugary foods. When you work nights they fuck you up more than you realize.
4. Acceptance. You're working an unnatural work schedule, I wish I could say it got easier, but it doesn't. Working nights destroys your body and cuts years off your lifespan, because we as a species evolved to sleep at night and hunt/gather/work during the days. On top of that, a lot of jobs that are overnight tend to be horribly repetitive and/or require sitting for extended periods of time. Those two things alone will drop you in your 40's if you're not careful.