actually, caffeine sounds like a bad idea, under the circumstances.

I would vote for some meditation.

Stop stressing out about what you haven't done. Just sit and be still for 5 minutes. Do some breathing. Feel your feelings - identify the feelings that you're experiencing. Is it anxiety? Pressure? Boredom? Don't punish yourself -- just identify them.

After sitting still for 5 minutes, focusing on your breathing, get a piece of paper and write down a plan for yourself, giving yourself some timelines.

Definitely make a point to get your sleeping schedule back on track.