I had it some years ago and sorry to say it took a long time to get over it. There is also the issue as to why it's happened, which is what your physio will likely try to find out. It's not really an overuse injury it's often a sympton of weak quad muscles for example. You then need to work on that to prevent it coming back again.
I personally wouldn't risk the half, I did so doing Reading last year and it led to way worse problems aftewards which took 6 months to sort out. However, see what your physio says, but if you currently get it within a mile then I doubt it, sorry.
I got through a two pairs of sennheiser pmx 680 before I got these
http://www.johnlewis.com/231464002/Product.aspx
They have the iPod controls and I think have a mic if you use them with a phone. They are 100% waterproof (the instructions say they're machine wa shable) They come with a few different sized fittings and do require a but of trial and error to get a good fit. Once done though the sound is a massive improvement on the sennheisers. Having said that - they're more than double the price.
Thanks for the link, they look great, but a bit out of my price range tbh. I've gone with another pair of the 680 for now to see how I get on.
I second what Emmy says. Definitely check it out correctly. I overpronate on my left foot & couldn' t believe it when I saw the video. FWIW I have Nike zoom shoes which are great for me.