The past year i've been unmotivated & depressed never feeling up to go out & do anything or spend time with anyone, why have i changed how can i help?

Depression: Based upon your description, it sounds like you are depressed. This is common in teenagers, regretfully. The important thing is to get help. I would discuss with your family doctor first, but you may need to talk to a psychologist, counselor or social worker. This is common, and you can get better--but asking for help is the next step.