Sorry to hear this ... it's painful. Mine started in my early 30's. Saw orthopedic who suggested surgery but said he couldn't guanantee results & primary doc thought it might be early osteoarthritis from decades of high impact sports/exercise. Steadily got worse, had difficulty going downstairs, couldn't do step workouts, not even on the 4" platform. Steadily gained weight, making it worse. Then a few years ago, a new-to-me primary care provider suggested I lower my carb intake for other reasons. So I gave up grains, processed carbs and sugar, AND miraculously, to me at least, as I was going downstairs one day about two months into this process, I noticed I wasn't "one-legging" it down the stairs. I went up,down, up & down again like a normal person- I hadn't done that in years. I then took collagen daily, and it steadily got better. The doc thinks it was inflammation due to the higher carb diet. Other conditions improved also. You might consider lowering your carb intake also by eliminating grains, sugar, processed foods and taking some collagen supplement. Two years later, I am still amazed at how little knee pain I have - doc thinks the remaining pain is probably osteoarthritis considering my age, 63, and previous history of high impact activities. Good luck, I hope it heals fast.