Help! I hurt my knee!

Help! Last Tuesday (In Jazz class) I did something wrong and hurt my knee. I thought it was no deal, but I think I was wrong. But, on Thursday (Mainly in Pointe class), I noticed it hurt even more. So, in a Nutcracker rehearsal, it hurt even worse. And I did a workshop and it STILL hurt. So, I told my mom and she said that if it still hurts this Saturday (Nutcracker rehearsal and a few workshops) then she would take me to a doctor. But, It hurts all the time and it hurts when it’s straight AND when it’s bent. The question is:

1. What is wrong with my knee?
2. Is it too late to fix my knee problem or am I just in time?
3. I’ve tried RICE (several times a day) and it doesn’t work. What else can I try?
4. Any advice and anything else? Thanks, but I forgot to mention that I’m not on my knee at all! I stopped dancing till Saturday & Sunday for my Rehearsal and workshops. If it hurts then, I will go to a doctor. But, it even hurts when I walk or when I go up the stairs! It is my left knee. And it is like a strip of pain on the inner part of the knee. Please help! Please oh please help!!! I need to know!!!