How to stay awake after little sleep?

It's almost 6, and I have to be at school by 7:45 today, rather than my usual 8:45. I set my alarm for 6:30 and couldn't sleep till like 12:30, and then I woke up around 3:40. I tried to fall back asleep but I just couldn't. I'm not tired now but I know I'll be practically dead later if I don't do anything now to prevent it. Also, how can I look more awake? Like how to waken up my puffy eyelids. Thanks.