Am I depressed? Hormones? Teenage angst? Well... you tell me! Please.?

A lot of teens are angsty, so people tend to dismiss teenagers who feel the way you do. It sounds to me you actually have dysthymia, which is one type of depression. It's also what I have (at least I really think I do). Your back problem is very likely rooted to your dysthymia also. I'm a a few years older than you, but I feel basically the same way. You and I both need to see a doctor because experiencing all those symptoms for such a long amount of time (in my case 2 years) is no way to live. They will most likely help you (and me) with helpful suggestions and possibly give prescriptions for medicine.