08/26/2014 AT 02:35 PM EDT
Though her latest album is full of self-acceptance anthems, it wasn't too long ago that Demi Lovato
struggled with her body image
The "Really Don't Care" singer reflected on how far she's come after dazzling in a red, curve-hugging dress at the MTV Video Music Awards
on Sunday, thanking her Lovatics for teaching her that "staying strong is worth it."
Lovato, 22, posted an Instagram
comparing her four most recent VMA looks – and the insecurities she hid behind each outfit.
"This picture makes me feel so many mixed emotions. I remember the day I wore the dress in the very first picture. I remember asking for Spanx to flatten my stomach because I [used] to feel so heavy and 'fat,' " she captioned the photo Monday night. "Now looking at this picture, you can clearly see my hip bones. It makes me sad because I wasted so many years ashamed of my body when I could've been living the happy and healthy life I live today."
She continued: "It TRULY just goes to show you that your perceptions can lie to you. OR they can make you learn to enjoy life. Fortunately looking at the picture of myself in the red dress yesterday, I not only feel so grateful for the love and support I've had from fans, friends and family, but … I also feel … beautiful."
The pop star was treated for eating disorders and cutting
in 2010 and has battled alcohol and drug addiction
. But now, Lovato is feeling better than ever.
"I'm so excited to live my life the way I deserve to," she wrote, "and to the complete fullest."