With the way Britney Spears' career is going right now, it might be hard to remember what she went through nearly a decade ago.

The singer has been performing in Las Vegas at Planet Hollywood and she graced the stage at the Billboard Music Awards last Sunday. In fact, her performance there was deemed the "best of the night," according to Tuesday's report from Mirror.

Considering that Spears was dealing with a lot in 2007 with her split from Kevin Federline as well as shaving her head and bashing a paparazzi car with an umbrella, one may have thought her reputation as a pop princess was over.

But the singer has proven that message wrong by going back to her talented ways and she seems much happier.

"The happy, smiley, fun-loving Britney of yesteryear is back," one of Spears' dancers said. "It's been a long time coming, but it's like a weight has been lifted off her shoulders and she's learning how to be happy again. She is like a different person."

Spears apparently needed medication to function well, but that is no longer a major issue. Not only that, but she's letting people into her life without turning to isolation.

"After years of being heavily medicated- at times she was all but sedated- she is clean and actually living," the insider said. "Britney's now laughing and joking with all of us, and getting involved with everyone on tour. She's no longer cutting herself off. It's brilliant to see, and everyone is really proud of how far she's come."

With all the work she's putting in to get back on top, Spears is staying healthy and strong.

"She is back in the gym at least four days a week and has a personal trainer, in addition to all the dancing she does," the friend said. "She is incredibly fit and has reclaimed her abs from her teenage days. She is really taking care of herself and looks amazing."

Tags: Britney Spears Music