To be perfectly frank.
consider the idea you might just be sad for a little bit. A Lot of teens these days think they have depression because everyone else says they do and ( at least in my town ) the more "ptsd" and the more depression you have the cooler you are.
But if you REALLY do think you have depression try to realize life is a ride and you won't always be happy. there will always be ups and downs and its not really fair. once you accept responsibility of school,chores and come to terms with the unfairness of life you can start to be happy. Try to find something you enjoy. I was a little depressed and had a problem but i watched a anime about animation and i fell in love with the process of cel animation and music.
Try to find something you enjoy and look forward to it and live for yourself.
sorry if that was a little preachy/weird I got a little emotional.