Go talk to a doctor, counsellor or therapist. The internet can't diagnose whether this is clinical depression or something else - there are many reasons why you could be upset, everything from still going through the grieving process to hormones going crazy as you're growing up. It's probably a combination of many factors.
Don't be ashamed if things that 'ought' to work don't. One of the things I have learned from my father's depression is that things that 'ought' to help often don't; you have to find the thing that helps you, however odd it may be. Illness doesn't always follow storybook or layman logic.