I work night shifts too and I believe that it is acceptable to call in sick for no sleep. I feel like I shouldn't be risking my licence just to go to work if I couldn't prepare for it. I went to work on no sleep, had redbull and stuff but it didn't make me comfortable and I try everything to sleep during the day.
I met my boyfriend on another non nursing related job. Luckily, he works nights and so do I. The only thing I could suggest is to meet someone in the hospital