Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.

A couple of things come to mind. By your post, you seem to judge yourself by what you see in others. The problem with that is you don't see others at all times.
Learn and live by this: The past cannot be changed. The future cannot be arranged. The only thing we have control of is this moment. We can expect a lot from the future ... but they are only expectations.
There is a POSSIBILITY you are having some CLINICAL depression. If so, you MUST consult a doctor to find out. SOME causes of clinical depression are physiological ... thyroid function for example.
As a teen, your body is developing and you may be experiencing some TEMPORARY hormonal issues. ONLY A DOCTOR can conclude what I am talking about.
Whatever is going on ... your mental state is obviously bothering you ... teen depression is WAY off the charts today. We live in so much uncertainty, .. just about EVERYONE is subject to depression.
The best thing for you, in my opinion, is to describe exactly what you have posted to a medical doctor. Some diagnoses are in order.
Clinical depression IS treatable. Without treatment, it can become deadly.