Hello, I'm A 16 Year Old Girl. About A Year

Hello, I'm a 16 year old girl. About a year ago I was perfectly fine, I was active, I was full of energy, I loved my sports, ️and concentrating in school was easy. I'm a straight A student in high school and I always have been, but for the past half year or so I've been so different . I have a healthy wieght im 5'3 and I'm 125 . I exercise and im in track. But I've been tired constantly no matter how much sleep I get, I sleep too much sometimes, I lost interest in my sports, and I have no appetite most of the time. I look pale and drain . I checked if I have anemia and I don't . So I don't know what could possibly be wrong with me . I know it's not my hormones changing because it's been such a long time I've been feeling like this. It's not like me. Can anyone help?