Recurring Knee Problems (~12years)

Hi there, sorry for yet another knee question but none of the other threads quite match.

I orginally injured my right knee playing rugby about 12 years ago, cracked / chipped the top off my pattella, which is still in there floating about.
After this initial injury I started to brace my right knee for a while, the pain then moved to my left knee.
I was told at the time that this was due to one leg trying to compensate the other, and that I should learn to live with it and carry on training.

Since then I have had persistant problems with both knees that has been getting worse the last 12 months or so. Training and the gym have had to go out the window. My GP has reffered me to a physio as he belives I have muscle atrophy in both quads.

It has gotten to the point where driving, walking up and down stairs or even walking are difficult, at the weekend I walked about 4 miles (slowly) with my wife and daughter now my quads and knees (just above, possibly ligaments?) are causing me alot of pain.
I have been prescribed diclofenec and paracetamol but they aren't helping much.

Does anyone have any idea's of what I could do in the meantime as my physio appoitment isn't for a few months? Any advice would be greately apprecited.
I'm 26 y/o male, 5'11", 12.5-13 stone.

Thanks in advance for any replies and sorry for the long first post.