Honestly if you are getting some seriouspain that is stopping you from running then you needto have that sorted first! The thing about knee pain isthat even though you think that it is bearable, subconsciouslyyou still put less weight on that leg thanyou normally would and so before long you startpicking up injuries in other areas of your body due to thechange in gait. Knees are problem areas anyway and so it is bestto see a physio as they will be able to work out ifyou have a muscle imbalance that iscausing the problem or if it needs further treatment. Thequicker you get your injury sorted out then thequicker you can get back into training!
Your schedule looks good and I would bereluctant to make any changes before you have hadsomeone take a look at your knee. Maybe in themeantime whilst you are receiving treatment you could try somethingnon-impact like swimming to improve your fitness before you start uppingyour distances again. Just a thought...
Hope that helps and goof luck with thetraining!
I am currently training for the Londontriathlon and keep a very boring running/triathlon/moanings blogcalled Londontri.com.
Goals:
Sub 2:30 London Tri
Ironman UK 2014
Brighton Marathon