Hi Mr. Nap,
I'm not sure anyone on this board is really qualified to advise you about your knee. Certainly the best thing to do is have your doctor check it out. I wonder if you might have somehow re-injured it, and that might account for the new pain. It sounds awful, and I'm sorry you're going through it. I assume the doctor you see is an orthopedist or sports medicine guy, rather than your primary care provider. It sounds like a kind of specialized question.
Regarding pain pills...I hope you don't have to go there! I hope your doctor can give you some exercises to get your knee tracking right, or send you to PT for help. Any opiate or opioid pain med carries the risk of addiction, especially if you need to be on the med for a long time. People's susceptibility to addiction varies, but I think most of us on this board would say it's not a good thing to start if there's any way you can avoid it.
Just a thought, from my own experience. Some doctors are now proscribing a "new" pain med called
Tramadol, a/k/a
Ultram or
Ultracet. For some reason its manufacturer tells doctors that it has no addiction risk. This is just scandalous, because it can be massively addictive and truly horrible to get off of. If your doctor offers you Ultram, make sure you talk with him about the potential for addiction. If he says there's nothing to worry about, you should check in with a different doctor. This is a huge problem across the country.
I hope your knee mends and you start feeling better soon. Please let us know how you are.