The Nvidia gt525M are hybrid cards, you have a Intel and a Nvidia card running in your system, the drivers you are installing for you Nvidia are not working correctly because they are not being loaded on startup.
You Intel card is running as primary so you have 2 options:
1) If you BIOS allows to turn off the Intel card and leave the Nvidia one running then the drivers will work correctly;
2) Use software that enables you to use some functions of your Nvidia card, its called Bumblebee and its largely discussed on use/installation, etc, on the site.
At the moment to recover your GUI you need to login in to recovery mode and delete your
/etc/X11/xorg.conf file, after you have done this your computer should boot to your desktop using the Nvidia card.
For more information on how to boot in to recovery mode follow the procedure explained here
and once you get a prompt
rm /etc/X11/xorg.conf to delete your
Reboot with the command
reboot and read up on how to install Bumblebee (if you cant disable the Intel card in your BIOS) in the post above.