It could be artritis satting in also. I have it in both hips. I also get the same problem you have at times. Mine comes from not moving around enough at times. It feels like I have pinched nerves a lot of times also. I have had triggerpoint injections in my hips to calm down the inflamation that comes with the arthritis.

It could be the RSD spreading. I don't know how in tune you are with your body yet but I can soon figure out what is RSD and what isn't with mine.

Use a sleeping pad on that side. Also I use Lidocaine patches. I throw one of those on and in no time the pain lets up especially if it's not RSD.

Ada