Westcoast 10K run

After running the London marathon in 2002 I vowed I would never get nervous about a run ever again - but here I am - three days before the Westcoast 10K challenge, which is part of the Great British 10K run - a nervous wreck.

I seem to be losing my fitness - unable to practically walk to the end of the road without feeling the need to stop. I can't even cycle to work without my legs wanting to rest.

This is purely psychological because I went out for a 1.5 hour run on Sunday and did just fine - covering just over five miles - so I'm not worried about completing the run - I don't know what it is!

If anyone has any tips on how to overcome this - I would be very grateful!