Worked nights for years. What to do? Benadryl, and plenty of it! Blinds, shades, and blackout drapes. Put towels up over the tops of the curtain rods (hanging down the sides) to block ANY light from coming in. Would even put one against the door to block light from hall.
Make sure you're not hungry, make sure you use the bathroom, make sure you've turned the ringer off the phone. I kept my answering machine in another area of the house so I couldn't even hear that. Air conditioner or fan for white noise.
If you DO have to get up for something (like the bathroom), keep the lights OFF. Getting shocked with daylight during your sleep cycle can screw you up. I used to keep my eyes closed, lol, just to be sure