Mike, I'll answer this as if you asked" How can I properly taper for a long-distance race?" rather than "How can I further destroy myself?"
The fact is, at this point, there is nothing you can do to improve your fitness for the race. The fitness you have at 10 days out is the fitness you bring to the start line.
Taper: depending on your regular mileage, your taper should be 2-3 weeks. Heavy, marathon-type mileage requires a longer taper.
Two key workouts-last long run 2 weeks before with a 5-7 mile run at planned race pace at 10 days before.
Trade out tempo runs for tempo intervals, 3 workouts in the last two weeks.
(ex: 4 x1200 at tempo pace) These will maintain your lactate threshold and running efficiency. Last tempo workout 5 days before.
Otherwise, easy mileage and several rest days with a 4 x 800( 800 recovery) at planned race pace the day before the race.