Shoot I said a really bad word at school today and now im in big trouble what should i do?

i called this girl i dont like a mudblood because both of her parents are muggles, its not that i have anything against muggleborns, i just really dont like this specififc person. she always casts hexes at me inbetween classes and even poured a baldness potion in me pumpkin juice! ( i was bald for a week ). so when i called her that of course she told on me to professor snape (he is thehead of her house and HATES gryfyndors like me)i got 2 weeks detention AND was suspended from quiditch for a week as well. thats the worst part because im the captain of my team and if you dont have a captain then you arent allowed to practice and my team NEEDS to practice because we havea game next week against Hufflepuff. So what do i do to be allowed to play quidditch again. thanks