If that does not work, a nice relaxing herbal tea can help sometimes.
Also, if you are like me at all, putting the phone/tablet down or at least on to nightshift can help a lot.
Ironically, despite that I am not in school for...cough...a while ;P ...I am in a similar boat to you at the moment. After having been laid off at the beginning of June I have been taking my first "Summer Vacation" in...all the years.. But now its time to get serious, I can not be a night owl....as I sit on here at nearly 1 in the morning.
Good luck!