This is not a discussion that will ever have an end to it, and you'll never convince anyone saying they're ugly that they aren't. Sometimes it even fills a need because, if I'm ugly, then it isn't my fault—and so I don't take responsibility, and won't face that I actually have to do something to attract people.
The other reason the ugly thing is pointless—it's 100% judgement, and doesn't objectively exist. Now I know, "hang on, that's stupid—it's been shown that people are inclined to find symmetrical faces with a certain range of features attractive, as well as bodies that exhibit the likelihood of reproductive health…" and walk into any high school or college and you know instantly what attractive is… Sure. That is true. But it is also true those are values, narratives, that could easily go another way.
The first thing you need is an understanding of who you can attract, and who you can't. If you insist on punching outside your weight class, you're going to be disappointed, guaranteed. You have to learn how to maximize on your appeal, and focus on what you do have, not what you don't.