How do I come to terms with being ugly?

I never used to think I was that bad looking, but I've been called ugly (and many worse variations of ugly) for a long time now. I've been called ugly by children, teenagers, and adults, by men and women. It makes me sad inside, but so many people have said it that I now have to recognize it as truth. How can I accept my ugliness and learn not to get hurt by these comments?