Seeing a psychologist would be a first step to talk to them and get a diagnosis, if that is what is going on. Clinical depression is caused by a chemical imbalance imbalance in the brain and you would need to go on anti-depressants in order to start feeling better. We all have our down days and tough times, but that does not always mean that you have depression. Try keeping a journal and writing down all that happens in your day, the good and the bad. This can help you sort out your feelings and maybe also see anything that may be causing problems in your life. If there is a certain person or friend causing problems, avoid them and leave them behind. Life is a lot of what you make it, so make decisions wisely and do things you enjoy(hobbies, games, etc). Take care.