Eat Sleep Run?

One of my biggest challenges in preparing for my first Marathon has been sleep....Ive done every training run, lost a few kg's, changed my diet, done my core training but Im still getting only 6 hours of sleep a night.Im pretty sure on my last long run i actually drifted off while running in the last five kms....

In Running Times there's a great article on how important sleep is:

Studies specifically linking sleep deprivation with performance in endurance events are scarce, but in one of them, published in the British medical journal The Lancet, researchers found that a period of decreased sleep lasting only a few days interfered with glucose metabolism and raised levels of cortisol, a hormone released in response to stress that may interfere with athletic recovery at high serum concentrations. The study suggests that glycogen synthesis is impaired during periods of reduced sleep, meaning an athlete in these conditions is operating with less than a "full tank" and may "bonk" earlier than a well-rested

Last night i woke as per normal at 430, knowing i am doing my 34 longest run this avo and dreaded the idea of only getting 5 and a half hours but thankfully drifted off again.....thank goodness..I wonder how I'll go the night of the Marathon? Any hints?