If I'm being honest, you don't exactly cope with it. You just kinda wake up one day and go "well this is my life now." Tbh life is too short to worry about how every point in your body looks. As long as you're healthy thats all that matters. I'm 25 and still dealing with the fact I don't look how I did in highschool, my hair is even starting to go grey. Theres no point in stressing yourself out about it as long as you're still healthy, or else you'll dig yourself into the ground. The LAST thing you want to do is obsess about it, because bottom line, no one looks how they did in highschool once they've become an adult. I know it sounds like very cliché advice, but you just gotta focus on the good/parts that you like ¯_(ツ)_/¯ If you strive for perfection you'll never reach it, since perfect will change once you've gotten to where you think you should (hopefully this all makes sense im very tired lmao)