On another note (and sharing the pain) I had the worse ride ever this morning. It was fasted but I didn't feel hungry. Just had absolutely nothing in my legs. Which I'm taking to be a good thing. Adaptation can take a good month usually ( I'm 15 days into Whole 30) so half way there.
Lee - I've always tried to focus on real food in this stage so as not to fall into the 'sugar' habit.
I'm by no means an expert (and everyone tends to do their own thing) but salted cashews and a couple of dried apricots have worked pretty well for me. PT Pete swears by cubes of butter, mayo and corned beef
There is always an element of legs feeling shit at this stage and you will get through that.
Have you had the Osgood Schlatters recently diagnosed?
And for what it's worth, significant amount of knee injuries are related to muscle imbalance problems. It's always worth investing in a strength/conditioning and stretching program alongside the running (if you don't already).