It looks like your profile got corrupted. It's a rare occurance, but it can appen.
From the administrator account, create a new account for yourself.
MOVE all your personal files to that new account. As the move is a same drive move, it's actualy very fast.
Log into that new account and check that your files have been correctly transfered.
Once you are confident that the move have successed, you can delete the problematic account. It can only be done from the administrator account.
Be sure to sellect the option to KEEP all files from the deleted account. This option will ensure that any file that you may have forgotten will be preserved.
Electro, October 2013