help!

I've got one month to train for a 13.1 mile run.

I've had a new job, working away etc etc and have sooo left it to the last minute.

anyone got any good advice at what sort of training I should do (distance and frequency) to get ready for it.

i can do 7 mile in one go but that nearly kills me lol and takes 50 mins.

any advice muchly appreciated!! oh and any food good etc for endurance?