Medial Meniscus Tear?

I'm a 17 year old female dancer and I've recently broke my foot. For years now, my left knee has been having occasional pain, but I just umed it was just wear and tear from dance, especially since I dance non-stop with an emphasis in tap. While I was on crutches for my broke foot, I fell when it was raining and landed on my knee. When I went down I felt a "pop". I just iced it and figured it was just bruised. It hurts worse when I sit with it bent for a long time. Each time I bend it, it will grind until eventually it will just crack as if it's popping out of place. Yesterday I went to my follow up appointment with my orthopedist about my foot, and I mentioned my knee just to see if he had any exercises I could do to make it heal faster. He decided to examine it and he said he thinks it's a torn medial meniscus with additional torn cartilage. Whenever he would do some range of motion exercises, it would keep popping in and out. I go for an MRI tomorrow to determine exactly what it is. He said worst case I'll have to have that arthroscopic knee surgery, which I know isn't too terribly bad, but the question is how long is recovery? He told me I might could be doing very light dancing within 3 weeks, but I've read stories that say sometimes 6 months! I know as a dancer I have to take care of theses injuries, but this is my senior year and I turn 18 in 2 months, and I already have several auditions lined up. I guess my question is is there anybody who has had this? How serious is this and how long will I be out? How much more damage would it cause if I wait several more months to have the surgery done and will it effect recovery time? Sorry for all the ranting, but I'm just really curious. Thanks in advance :)