Mac user account problem

[las aron]

So my school mac (OS X) is running on this network system that connects all the computers together or something like that. It having a lot of problems this year, I decided to create my own admin user so that I wouldn´t have to deal with all the stress. It worked perfectly until sometime last week, when forgetting that my battery was low, I logged on and it turned off after mere seconds, after this it´s like the account doesn´t exist. I´ve even created a new admin account to change passwords on the malfunctioning one, and it still won't work, like, I can see it when I go to system settings etc, change it from admin and back, change password and picture and everything, but trying to log onto it is hopeless. If anyone has any idea what might be wrong, please help, it´s really annoying, I have a lot of projects, texts and files I´d like to keep.