I'd recommend not using any spell-checking while writing long texts (that's only useless distraction). And the right music. For me, that would be high-power Eurobeat to write faster. I'd say listening to long 3-hour-podcasts about a personal liked topic also helps to increase the attention span. And also take it easy. Whipping it through in 3 years versus easy time in 4 years with plenty of room for awesome activities aside studying, nah, which way do you prefer?
Also, learn how to deal with failures. They will happen, without a doubt, in school, in university, in business. Unfortuneatly no recipe for that. I race bicycles, so going forward is always the natural thing implanted in the mind, even after falling down. But that's just one of many sports to learn this important lesson about how to get up after a failure...