I don't think you're ugly at all, I agree with willow, your really cute.
Maybe your just not as "agressive" as the other girls are, which is fine. In my town, girls tend to make the first move when it comes to kissing and whatnot. But im not saying be more agressive, do whatever you feel comfortable doing. Your only 15, you still have plently of time to have a relationship. I know plenty of girls your age who havent had boyfriends yet. And for the 2nd time your not ugly at all
Hope i helped