Hi, I'm A Fourteen Year Old Girl. Over The Past

Hi, I'm a Fourteen year old girl. Over the past few months, I have been feeling very differant than usual. I think I may have depression but I'm not sure. I am perfectly fine when I'm socialising with my friends , but then I may come home and feel very upset. Some nights, I get very upset but not always. I have noriced a huge change in my appetite.. Eating less. Im always feeling very tired and have a lack of energy. In school recebtly, I find it very hard to concentrate and have no motivation in succeeding in school anymore. I really don't care about school or being successful there. I think about my future being bad because of my education and me not willing to work anymore.. Please help