Help please with 360 waves!!!!

Hey fellow wavers! (ok that was corny).  I used to have great waves but I slacked a little and so did my waves.......I have been getting a little discouraged because my hair isnt waving up anymore. It maybe because of my job at taco bell requires me to wear a hat and sweat comes with it. I havent been able to wave up at all. But here's my routine Once a week i will wash my hair with this duke shampoo, then i put the sportn waves (black can) in it and after brushing i wave cap and du rag it (simultaneously). I guess i think it'll add extra pressure. But all my hard work is for nothing because after a week of working at tb its all gone. So I really need help Please!!!! What could I do so that I can have great waves while still working???? I can't quit and i cant wear durag or wave cap under my hat.