RIHANNA struggled to enjoy the month-long vacation she took at the start of 2012 as she was ridden with anxiety thinking about work.
The We Found Love hitmaker invited a group of friends to join her on a Hawaiian holiday after she wrapped up a lengthy world tour promoting her Loud album.
The singer tweeted photos of herself soaking up the sun in a bikini and goofing around on a surfboard, but now she reveals the time off was torturous because her mind was racing with career concerns.
She tells Elle magazine, "(I had been) dreaming about it for the entirety of 2011... (but) I felt awful. I kept thinking, and that drove me nuts.
"I kept feeling like something wasn't getting done, like I was being irresponsible. I knew this was going to be a big year, and I felt like I wasn't doing anything about it. I had such anxiety, I was going crazy."
However, Rihanna admits there was one daredevil activity she enjoyed on her holiday - swimming with sharks.
She says, "You have no idea the thrill! Let me ask you something. When you know you like a guy, or when you've been in love - that feeling when you see that person, what's it like? Is it the same feeling you have on a roller coaster? That's the same feeling you have swimming with sharks. That's the same feeling you have when doing anything daring, risky, spontaneous, or unpredictable. I think having those butterflies is the closet thing to being in love."