Who am I kidding

I tried to run this morning but it didn't end well- there were no sobbing tears, but I did feel a bit sad.
My knee pain is not going away and this morning I couldn't tape it successfully so it just hurt with every step. I only managed 1km before I turned and walked home.
I am pulling out of the Half Marathon- it just isn't sensible to think I can run that far with so much pain. I can pretend for a little while that it doesn't hurt, but for over 2 hours? No. So I am so sad about missing out on running into the G- I so wanted to run on the new course but it just isn't going to happen.
My 3 months recovery is starting today- just got back from Pilates and will try to go for a swim later on.