Can I take Promethazine 25mg with a 500mg Naproxen? I actually already took a Naproxen maybe an hour ago?

Promethazine is an appropriate treatment for nausea. Pepto-bismol may help also. Why are you taking Naproxen? If it is because of stomach pain, Naproxen might be making it worse--I would recommend avoiding Naproxen (and similar drugs like aspirin or ibuprofen) for anyone with a hiatal hernia.