We're all born so beautiful. The greatest tragedy is being convinced we're not.
The concept or definition of beauty has changed so much since the 1980s (for example). It's forever changing, just like fashion. We've gone from "being slim" as an in-trend to "curvy" to many other body shapes and figures. In the Bible it states that we're born in God's image, and in the Quran is states that every creature is beautiful because Allah created it.
Yes, we go through "phases", especially during our teenage years where we feel uncomfortable or like we don't not belong in our own skin or you think to yourself that you're not beautiful. Stop the negative thoughts! Stand in front of a mirror and repeat it daily, "I am beautiful."
Beauty is not just a visual but it's also your attributes and character. So talk to yourself or think and list 5 positive things that make you who you are...(for example: knowledge, kind, caring, a good listener, and compassionate).