Knee Pain

So on top of the golfers elbow which is still causing me discomfort (My physio shrugged his shoulders after 9 weeks of sessions and sent me away with some stretches), I now have pain behind my right knee and a similar, although less painful pain, in my left knee. It hurts most when I rei at the beginning and end of class. No idea how I did it but my leg also feels a bit tight from the top of my calf, through behind the knee to the bottom of my hamstring. I will make a GP appointment but wondered if anyone had any ideas.