I Woke Up To My Knee Having Shooting Pains And

I woke up to my knee having shooting pains and I could barley walk and when I do it pops and sounds like it's rubbing together, I went and got an MRI done and they said it was clear but yet I'm in a brace and on crutches. I can barley walk or even get out of bed . I don't know what to do since the MRI is clear