If anyone has one that they want to sell on and aren't looking for too much (I believe they are expensive new), then please let me know. It's for a friend, but I can pass details on. She's in the Beaconsfield area.
It's really hard to comment as a 'knee injury' is very generic but I have seen a knee specialist a few times this year as I damaged my knee after being knocked off my bike earlier this year. The specialist said that he sees many patients with really bad knees (obviously) but if they keep the muscles strong around the area, especially the VMO (i think that's what it's called, the muscles above the knee on the inside of your leg), dodgy knees dont have to cause problems.
Oh and going faster, more running and speed work. I used to hate speed work as it was so painful, but then I learned to quite enjoy it. Get some track sessions or try going for a run and do several ks in 5 mins, broken down with slower parts. Your legs will get used to turning over faster.
Personally I find the only way to stop bad food cravings is to cut it out. I know this is obvious but if I eat chocolate one day, i just want it the next and the next and the next. The cravings will stop if you go cold turkey. Sugar is addictive. Try and go a few days without it, telling yourself that these days will be the hardest. It should be easier after a few days and by then you will feel much better and hopefully not want to put cr*p in your body.