Werdna covered what I would have in my earlier post. Psychologically, too, it's good to LNOW he exam can't beat you no matter what happens (saved me x100).
Stick, try get your timing down to 50-55 minutes (this is a real race) but keep the quality the same. (Or, get up to a 9/10 standard, then decrease the time)... Once you've done that, psych yourself up for two essays consecutively in two hours. Think of it like SAC prep, just a bit harder. Really psych yourself up, think of it like a challenge at the start of the two hours and COMMIT. Have some low-GI foods for brekky, have water during the exam, maybe an apple beforehand for a sugar spike, get PUMPED. Then do the double-essay. Do that successfully once or twice, then consider *optional step* doing a double essay + one-two hours break -> third essay. If after you can write te double-essay, and you want to skip the aforementioned step, get yourself super psyched and well-fed etc (consider it like an athletic event; you might consider water-loading te nigt befor. Not for any practical benefit, but to get you in the mindset of success), then attempt your full exam.
(Just for Stick, people; this is just a plan I devised for this particular issue)