ok i'am krazy but not stupied

but now i'am starting to question that

. I've decided to run a 15 mile marathon for the charity i work for

. i've been training over my holidays but still 15 MILES AHHHHHHHHHHHH

! so anyone here got any tips. My workout has a full run around my local park

. (Not i'am not going to eat raw eggs euuuuuu

).
Aerobics ( i enjoy doing it, plus i can shake my bootay

).
And healthy eating

.
anyone here done a marathon? even if you havent give me some ideas.
My brother came up with the best one. "Hay run for the first 2 mins because you will be on television, but the order a taxi and let it take you a block away from the finish line." Yeah right like i'am gona cheat