I Am Thirteen Years Old And Lately Feel Like I

I am thirteen years old and lately feel like I don't fit in at school. I used to love school and now I hate going. I think about school and get sick to my stomach and vomit. All I want to do is stay home and be alone, just being all alone makes me feel a little less sad. My mom is worried about me, but has to go to work and feels sad she can't fix my problem. I love to play on my video games and watch utube videos before I go to bed and then I can't go to sleep. Too tired to get up in the morning and sometimes I don't hear my alarm. please help