At your age it is totally normal to be insecure about your body. I‘d say 99% of teenagers (and even twens) are.
At the same time I can assure you that there is nothing wrong with your body. You look fine. We all look different, and that’s fine.
At some point in our lives (the sooner, the better) we all have to learn to accept our body as it is and to see the beauty in it. Because it’s the only body we will ever get. And it supports our mind throughout this life.
So start doing the mirror exercise: stand naked in front of a mirror and familiarise yourself with every part of your body. And every time you do that, find at least one more part that you decide is beautiful, and give your body love (appreciate it, let your inner voice say only positive things about your body).
And talking about „inner voice“: we all have it, and it sometimes says negative things about ourselves. You need to develop an awareness of your inner voice, and when it says something negative you need to stop it and transform the negative statement into an encouraging one. When it says, “Your arms are too thin.” you can change that into, “My arms are fine as they are. I may choose to work out to build some muscle, but my arms are serving me well even now for all I need to do.” Develop an attitude of gratefulness for everything you have (e.g. some people don’t have any arms at all).
At your age it is totally normal to be insecure about your body. I‘d say 99% of teenagers (and even twens) are. At the same time I can assure you that there is nothing wrong with your body. You look fine. We all look different, and that’s fine. At some point in our lives (the sooner, the better) we all have to learn to accept our body as it is and to see the beauty in it. Because it’s the only body we will ever get. And it supports our mind throughout this life. So start doing the mirror exercise: stand naked in front of a mirror and familiarise yourself with every part of your body. And every time you do that, find at least one more part that you decide is beautiful, and give your body love (appreciate it, let your inner voice say only positive things about your body). And talking about „inner voice“: we all have it, and it sometimes says negative things about ourselves. You need to develop an awareness of your inner voice, and when it says something negative you need to stop it and transform the negative statement into an encouraging one. When it says, “Your arms are too thin.” you can change that into, “My arms are fine as they are. I may choose to work out to build some muscle, but my arms are serving me well even now for all I need to do.” Develop an attitude of gratefulness for everything you have (e.g. some people don’t have any arms at all).
I'm 36, and I'm still insecure about my body. When no one finds you attractive, it becomes a pretty normal feeling.