There are lots of ways to address this, but almost nobody is talking about them. They're acting like the problem is insoluble and it's not. It is entirely human-created and thus humans can stop it any time they please.
* Do you dislike how a device or program makes you feel? Reduce or stop using it. If you are the parent of a child with this issue, take the thing away. They will suffer withdrawal and be miserable for a week or two, but after that they should recover. There is now expert help if they do not, which may or may not do any good.
* Don't use photo editors. Learn to shoot good photos instead. If you don't like how you look, don't share the pictures. It does you no good to become a character in your own life, pretending to be something you are not to people who don't like the real you. That is soul-destroying.
* Don't spend a lot of time looking at fake photos. Instead, frequent sites that offer diverse body types and accurate imagery. You can also look at things other than people online. Cats are always popular. Looking at nature pictures can boost your mood. Read and make pictures inside your own head.
* Work on appreciating the body you have. There are lots of resources for this. If you're unhappy with your appearance, there are things you can do with clothing, makeup, healthy eating, exercise, etc. to make improvements. (Excepting certain things like gender dysphoria, which for many people requires expert care to fix.) But mostly, try to love yourself as you are. Nobody's perfect.
* Hang out with as diverse a crowd as you can find. Bodies come in all shapes, sizes, and colors. The more diversity you see, the harder it becomes to damage your idea of what people "should" look like. Don't believe me? These are all Olympic athletes. Fuck beauty standards, be yourself.
* Represent diversity. In your little corner of the world, share images of diverse body types, write about them, link to news from others with the same views. The more body diversity we put out there, the more resilience we create against this nonsense about making everything look perfect.
* Practice honesty. Social media involves a lot of lying, and it turns out to make people miserable. This is not actually new, just the details. Apply the old solutions; they work.
* Cultivate lots of offline hobbies. Garden. Jog. Do sports. Go birdwatching. Knit, crochet, carve, paint, make things. Cook food and eat it instead of just taking pictures until it gets cold. Live your life. Nobody cares what your face looks like when you're busy saving their bacon.
These are lifestyle choices that many people will not wish to make. But if you make unhealthy choices with your media diet, you will wind up just as sick as if you ate nothing but chicken nuggets. It's up to you.