You got it.
I don't know if this will or won't work for you, but I know that in general -- and for myself, through my life -- the way I tend to tackle that is by checking myself with two main things:
1) History (and also capitalism and white supremacy). Fashion is fleeting and ever-changing, and that includes with body types. There is pretty much NO body type that has not, at some point and place in history, been the fashionable, desirable one at at least one time. It's so easy -- especially if you haven't been around a few decades to experience those changes directly, or aren't familiar with history in this regard -- to get the idea that whatever the current body type is it is the ONLY one (it never is, but the one that makes white people the most money usually gets the most airplay, go figure) at the time and the only one that has ever been.
It isn't. So, right now, it's a whole lot of white and skinny (or white and skinny except for -- mostly surgically enhanced -- boobs and butts or white and skinny except for appropriating Blackness or other cultures in tiny, white-acceptable and profitable pieces). And it has been before. But it's also been other things before. I remember, for instance, a period of time in my lifetime where muscles and fitness took precedence over skinny, and in other cultures during my lifetime, including right now, that's not the ideal, either. But every "ideal" not only leaves someone out, it leaves most people out, especially over a lifetime. Even your skinny friends won't always look that way: in fact, some of them won't even in a few years. In cultures or other ideals where the ideal is for people to be bigger, go figure: the skinny people in those cultures feel like you do.
Long story made very short: beauty ideals are, particularly in the last 200 years or so, MEANT to make people (especially women) feel like garbage, not to feel included. They generally aren't how most people look. That's because they're meant to be something to make people aspire to so they spend money and time to make other people money so they can live their best lives on our dime and our eroded self-esteem and crummy body image because some people just really such.
. So, this stuff is working on you just like it's meant to, unfortunately. It'll do the same on your friends, too, who will probably have a hard time with all this too, in time, either because the beauty standard will change and then THEY won't fit it (ever read the Sneetches by Dr. Suess?), or because they will have gotten used to meeting it, but then, as tends to happen with bodies in time, their bodies will change and they won't fit it anymore that way.
2) What I know about how looking a certain way doesn't mean someone feels good about themselves: In a word, while it's easy to think that why you feel bad about your body is because of those standards you can't meet (and like I said, that is part of it, for sure, though it's more about how you internalize this stuff), know that a looooooot of people who do match a given beauty standard still struggle with poor body image. They STILL don't like their bodies. Sometimes that's because they feel like they are thisclose to meeting the standards, but something about them is never quite right. Other times, it's because they actually are working very hard to stay meeting those standards and it's stressful and dehumanizing and just feels on the whole, exhausting and crummy.
Positive body image doesn't actually come from meeting beauty standards, nor do they necessarily make it easier for people who happen to meet them. That's why people can even look like an ideal but still feel...well, like you are, like they hate their bodies. There are so, so many things that can give us poor body image: beauty ideals are only one of them.
How do you feel about any or all of that? Can I also ask how diverse your friend group and community is, as well as the media you take in? One thing I've often noticed over the years in talking to people with poor body image, saying some of the same things you are, is a frequent lack of diversity. Growing up, we went to the YWCA several times a week in the middle of a diverse city, so I was able to see so many different kinds of bodies, with so much diversity, all the time. If you don't have that or much of it -- if most of your friends look the same, most people in media you look at look the same, if you don't see real bodies a lot with some real diversity, like you can see on a public bus, for example -- it can make it so much easier to internalize and believe the lie of these ideals, you know?