If have a popped blister at the back of my heel from running. how can i get it fixed and sorted out asap as i am training for a big race?

Blister Runner: Rule out any general medical problems? OK. If the blister is closed, put a bandaid over it (there are some over the counter 'blister bandaids) - worth checking out. If you try popping it you run the risk of infection, so be careful. It may pop and drain on its own, and dry up. You can also do what some skiers do: Put a small baggy over your sock to decrease friction.