I had something similar playing softball 2 years ago. I was running through 1st base: tore ACL, partial tear MCL (inside of knee), tore medial horn of meniscus (inside, front of knee), and a bone contusion for good measure. It took 6 weeks before they could do surgery due to the swelling and then they fixed the meniscus tear. 2 months later they did the ACL reconstruction. After that came 9 months of physical therapy for 9-10 hrs a week.
If you tore the meniscus, you'll be out about 3 months. If it's a ligament, you're looking at 9 months+. Make sure you find a very good orthopedic surgeon and do all the PT. My knee is back to normal after everything. I've got a brace that I wear for most athletic activities even though I don't have to wear it. I'd rather not go through that again.