All those fears you have listed? That is part of the process of maturing in your age group as well. Your brain is just trying to figure out "emotions" and emotions "are' scary and confusing, especially at this age where the hormonal levels are very high. As far as your weight? That too is part of your body going through these hormonal changes. Most of the depressive thoughts are just about the individual being "tired" because they are going through so much during these years both physically and mentally. It is very common in many your age, they just tend to not talk about it and put on some kind of persona that seems to somehow work with others.