Hi Gav, sounds like you were in a similar situation to myself. Still active, but sport was becoming restrictive, and until I went to a PT, I had no idea how restricted I was getting. I consider that I decided to have mine done early also, rather than wait and possibly lose the window of opportunity. I'm 51, operated on Oct 10th, up here in Canada eh. I too am having difficulty with ROM on flexion, right knee to chest. I can only get 90 degrees, without crying! However, I am finally accepting that recovery from surgery was nothing compared to the PT I am going through now. This is the real work, and as hiphurts posted, a week can make a big difference. We/you may have to accept slow is good! The progress reduces down to an extra couple of degrees flexion per week, slow but progress.
As a wake up call on my decision, I went out on the squash court just to volly on my own. That night i had so much pain in my unoperated hip, none in the operated hip. I had forgotten what that was like.
I am finally trying deep massage. I think it is helping. Possibly give that a try also.