Hey - you don't have much time left!!! Why not try and aim to do one long run at the weekend (Saturday) - but don't do a whole 13 miles. Go for another 8 miler, then do 4 - 5 miles on Sunday - then try and take it easy for the rest of the week, maybe do a few easy treadmill sessions. Don't do anything on the Saturday before the race, just make sure you rest and eat lots of carbs.
One other piece of advice - if it's your first half, don't shoot off too fast at the beginning. Much better to try and do the first half at a very comfortable pace and if you have enough energy you can pick up the pace in the second half.
Good luck!