Oh, Mouseykins! I remember being 17 years old and all of the hormonal and mood swings that that entailed. It really was like riding a rollercoaster. I was depressed throughout high school.
You're right. It isn't fair. It sucks mightily. I mean, it was bad enough that I had zits and Algebra II, but then when you add depression to that...! When I was your age, people generally did not prescribe meds for depression, and they didn't recognize depression as a disease. I dealt as long as I could until I had a major depressive episode at the age of 18, for which I was hospitalized. Because of the forum rules, I can't write about all the details, but looking back I wish so much that I had gotten help with my depression sooner.
Mouseykins, there are lots and lots of other meds out there besides prozac, but to get them you need to make an appointment with a psychiatrist. In your post above you wrote, "I have been to a dr about this before..." How recently was that? You might want to go to one who specializes in adolescent psychiatry. When I was in despair recently about my depression and even thinking about checking myself into a hospital, I went back to my psychiatrist, and she explained that my meds had stopped working. I believe "poop out" is the technical term. Not very nice imagery, but I think you get the point. She and I are working on stabilizing my moods and getting my thinking patterns more balanced. The same could work for you. I no longer drink or drug anymore because both those interfered with my depression.
In terms of "not having any reason to be depressed anymore," well, my experience is that depression doesn't just occur in a vacuum. It takes courage and discipline to face your demons, but you don't have to do it alone, just like people who have diabetes and high cholesterol and cancer do not have to cope with their illnesses alone. Keep getting help and getting help and getting help until you feel that your meds/therapy are working for you.