05/16/2011 AT 07:05 PM EDT
It has taken a lot of work, but Demi Lovato
is feeling good about her body these days.
Less than four months after leaving treatment
for anorexia, bulimia and cutting
," the Disney star is excited to show she has her life and physique under control.
"I've been working so hard to get healthy and fit," Lovato, 18, Tweeted
on Monday, linking to a photo of herself
strutting in a teeny-weeny white bikini. "I can't believe I'm about to [post] this but I'm so excited… Here's my bikini time body!"
Lovato, who acknowledges the process of loving her body "hasn't been easy," adds, "It starts with a commitment to yourself.. Your mind.. And your soul. And trust me, I'm still working at it!! Haha."
She's also sending a positive message to her young fans. "I want any girl/guy out there who struggles with body image or confidence to know that it IS possible to find peace with yourself," she writes.
Admitting she was "completely ashamed" of her figure in the past, Lovato says she's "excited how far I've come."