Not sure why it took you so long to decide to heed the advice to see a doctor but I also don't understand what could be causing you to think it is a torn ligament. You would know if you tore a knee ligament. It sucks. And knees are not 10% as bad as shoulders. I had my shoulder reconstructed at 28 and it took 18 months of rehab to be able to lift my arm above my head.
Why so bad?
Because I tore my labrum playing baseball in college and ignored it. For seven years. So everything got effed up royally for seven years and had to be rebuilt. Had I gone to the doctor then, recovery from the arthroscopic repair would have been 3-4 months.