feeling depressed

i am a junior in high school and haven’t been to school or seen my friends in three weeks, and most likely won’t see them for months. I’m going to do a spring sport in college, but my season is basically canceled and i can’t hit my high marks to get recruited. I used to run three days and week and workout, but i stopped because i am so sad. i cried four times today. i haven’t only eaten junk food. I couldn’t do my ap calculus schoolwork without an explanation. i feel like i have no purpose.