It's very hard to be ugly, because you'd have to be a bad person.
Example: There's this girl at my school who has perfect skin, adorable freckles, amazing long ginger hair, and a small nose. Notice how when I went to describe her, I immediately thought to only mention the parts I notice, the parts that make her beautiful? If I didn't know her or even hated her, I might mention her forehead that reaches back to almost the center of her scalp, her very oddly grown teeth, her small eyes, etc.
The fact that this girl is one of the sweetest, most positive, most passionate people in my school makes her look like a flipping runway model. So please, the next time someone says that beauty comes from within, or beauty is in the eye of the beholder, listen. Chances are, to somebody, you look amazing. So let yourself feel good!