I need help! I think i tore my ACL!?

Could be your ACL or another tendon or ligament tear or stretch, depends on what kind of action you were doing at the time. I would definitely go to the sports injury clinic as they would have athletic trainers who see these kinds of injury's often. They will probably recommend that you go back to the doctor. But in the mean time go buy a brace that supports your knee so you are not putting as much stress on it as you would other wise.