I haven't had it in my knees before..but last year..I had a bout of it in my hips for around 6 months..it was just awful tryint to sleep comfortably! It certainly feels terrible so I am sorry that you are hurting:(
I did two rounds (3 months apart) of steroid injections, directly into the area, as well as took anti-inflammatories for those 6 months and that seemed to make it much better...I have since learned exercises for my hips to help prevent it from coming back and so far so good!
I hope that your Dr. can help you relieve this pain from it...I've been thinking about
the pain you had with your tailbone...did you find a good treatment for that?