try resetting the PMU/SMC. for this MacBook Pro which does not, I think, have a removeable battery
1. shut down computer, plug in Macsafe or USB-C power adapter to power source and to your computer
2. on built in keyboard, press (on the left side of keyboard) Shift, Control, Option keys and power button at the same time.
3. release all keys and the power button
4. press power button turn on computer.
I hope that you had a backup system in place and working, and that you did a backup. No? Hmmm....
other than that, try resetting the nvram, asking here again or taking it in
good luck to you on your exams and with your documents
John b