Demi Lovato has come a long way.

Toward the end of 2010, The X-Factor judge checked into a treatment center after a fight with a dancer on the Jonas Brothers World Tour. She left the tour and sought help at Timberline Knolls in Illinois, a center for women battling addiction and eating disorders.

Demi later told Seventeen magazine, "I'm not going to lie, I was self-medicating. I was doing things like drinking and using [drugs], like a lot of teens do to numb their pain.” She opened up about her struggles with cutting, depression, anorexia and bulimia, and said she found out during treatment that she had bipolar disorder.

Fast forward to last night's New Year's Eve, and a happy, healthy Demi tweeted about the changes in her life: "Two years ago, I watched the ball drop on TV in rehab and cried my eyes out. Tonight I'm on the beach with my closest, most loyal friends … sipping coffee and sharing how beautiful life is and how far we've come. Recovery is a beautiful thing friends.. Life is good, God is great!” The 20-year-old also added this message to her young fans: “By the way - just reminding teens out there that you don't have to drink on NYE to have fun. Be the difference."

It’s so good to see Demi find happiness and stability. Here’s to a great 2013 for her — and all of us!

Sources: ABC News, Seventeen, People, @ddlovato