I'm sure you're not ugly. I think that's self consciousness talking. The only people who are genuinely ugly are those with ugly personalities. Nothing is more unattractive than someone who treats others like sh_t.

I think the more we ruminate about how other people may see ourselves, the more we get caught in a downward spiral. Just be yourself and people will like you. If someone doesn't like you and you've done nothing wrong, then it's their loss. Best not to be associated with those sorts of people anyway.