Judging from what you said and the photos you provided, the first thing you need to make clear is that this is not called chicken breast. In fact, there is no need to say it is very complicated. Since it is called chicken breast, of course it is like a chicken. The breast, that is, the middle protrudes forward. You can know it by thinking about the appearance of the chicken's neck. Of course, you also know that you are not considered a chicken breast.
You just said that your breasts are thicker than those of people of the same age, and your back is a little hunched. In fact, from the picture, there is nothing abnormal. It is definitely not chicken breasts. It is just considered thicker. You are in relatively good health and have more chest muscles. There is nothing abnormal about you. Besides, you don’t have any other symptoms. These are not abnormal. Don’t worry, you are very healthy.