I hyperextended my knee! help please.?

well i am a 16 year old male and i am a cheerleader. i was tumbling and after i flipped i came down and i saw my knee just basically give out. it hurt like hell when it first happened but as i gradually kept walking on it it got better. so i decided to start tumbling then it started to hurt again so i stopped for a couple days. it still hurts and but i can walk on it and bend it just fine. i need to have it heeled for this weekend because i have a cheer showcase i need to be in, any ideas how to heal it soon ?