Susham,
Suggest you hook up with the Serpentine Running Club - check out the website: serpentine.org.uk
Best thing to do would be to go along to a Wednesday night club run (meet just before 7:00PM in Seymour Leisure Centre).
You should find a group of people as fast, or faster than you. Typically, the faster people will run the 7.5 mile "Three Parks" run at about 6 min. mile pace. There will also be a number of groups going at slower paces.