I've been fat and ugly my whole life so I feel you. My vision impairment makes me look strange too, and it's completely incurable and unmanageable. So I feel uglier when I have to squint, turn my head, or look really close at things in order to see properly. Plus people like to tell me how weird, ugly, and fat I look. When I was a kid, I was so caught up in this and would cry all the time about how I'm an ugly lesbian and I'll never get anywhere in life and no one will ever love me.
The reality is that there are many really ugly people in the world who are doing just fine. I didn't realize this until I began to work retail and saw all of the different kinds of people out there. People with bodily deformities, super fat people, people who stink, people with horrible teeth, etc... those kinds of people were paying $500 in groceries a week, always had a friend and/or family member around to chat with, and always had something to plan and do. They seemed happier than I am, that's for sure. Of course a beautiful person probably enjoys their life even more than those people do, since being pretty comes with privileges, but it's not like it's impossible to be both ugly and happy.
I don't like to say everyone is beautiful, because its just not true. And you may actually be ugly, maybe really ugly, but the fact is that the impact of looks on the trajectory of your life is minimal. Being sociable, friendly, and neurotypical is all you need to be a happy and successful person. Being pretty is not going to solve all your problems, in fact it may not solve any of them.
Body dysmorphia is a terrible illness, there are people who are absolutely stunning who are thinking the same way as us, all because of some wonky chemicals in their brain or trauma or whatever. Beauty is not enough even for them, it's just not explainable. Even dangerous, damaging surgeries won't change their minds, and in the end the "others" will end up finding them ugly anyways for a variety of different reasons.
What I try to remember is that it's the "normies" who spread around that stuff about how looks don't matter, because to a degree that's how they honestly see the world. And it's true! idk any non-body dysmorphic/non-asshole people who are overly critical of others' looks in the same way we are to ourselves. The rest of the world may look at you and see ugly, but it's within your control to change their perception afterwards. You can be ugly and smart, talented, funny, kind, friendly, etc.. and people would love to have that kind of company more than a beautiful person who does nothing but fixtate on their preceived ugliness and depression all the time. Of course we can't choose to not be mentally ill, but it's a consideration I guess. After all the only real way out of this is robust mental health care (as with all mental illnesses)