I have had this and at times my knee will shake because of the pain, like my whole leg will just give out. Unfortunately, I work 12 hour shifts and have to deal with it. It hasn't ever gone away but I have found some things that help:
gabriella support belt- can't recommend this enough
alternating ice and heat when I'm home and when I'm not icing or heating I sit on an exercise ball
before I got my support belt, the first time the pain was unbearable, I had to go to work with it, because I can't ice, heat, or sit on an excerise ball at work I brought a tennis ball and sat on that. I was having right-sided pain and placed the ball on that side between the cheek and the thigh. It helped me get through a few nights. I read about that on this site!
Mostly, I just try not to overdo it now because I know the pain will flare up, but now I can deal with it when it does.
i have also heard massages and chiropractors help but haven't gone there yet.