Hi
I think you should consider the advice from /u/refugefirstmate and /u/dark12222000 as it is very good. Please know moving forward I'm basing my response only on things I know to be true from my experience and my experience with you.
You're asking for advice and that means you've recognized a problem that is harming you emotionally and physically, and you want to improve yourself. I'm really proud of you. Many people never find the strength to ask for help. Think of yourself ahead of the game. You are doing great.
Okay
There is no easy cure for feelings and emotions that are deep and hurt our heart, make us sad and cause us to feel isolated and afraid. People are ugly every day. But feeling ugly is a different game. Be brave and ask yourself why you feel that way. Just the way you asked us how to get better. There's no point in doing something if we don't know why, without purpose. So ask yourself what will beauty give you? Do you struggle to connect? Do you lack confidence and feel it will give you that great way about you that you see in the movies? Maybe it's deeper. Keep asking yourself why.
The difference between feeling ugly and being ugly
I promise you there is no cure for the distress and hate and fear you feel besides time, consistency, honesty with yourself, actively choosing the right path and understand that every single person you meet are all in different boats, but on the same choppy ocean.
Choose a goal now that you know all your why's. Then set your path.
Think to the future
Okay, now you're beautiful. Cool. What will you do when you're finally not ugly? What is it you want out of life right now that if the barrier of being ugly wasn't in the way you know you'd have. Confidence? Humor? Success? Love? Security? I challenge you to imagine a place where you feel beautiful about yourself right now, today where you're sitting reading this. You never worry about yourself in the mirror, and the flaws you see in the windows as you walk down the street are gone away. And now I will pop your bubble in our hypothetical. You're not automatically confident, you still worry, and Once you're there in your mind ask yourself, okay NOW what do I do? The bus doesn't start at beauty, so what's your plan next?