There is a way to uninstall the current nvidia driver that you use.
Code:
sudo command -uninstall
Replace command by what you used to install the driver (NVIDIA-Linux-x86-275.09.07.run ?)
Next you can try to start X
Code:
sudo service gdm start
You should at least be able to get to a desktop now (maybe via recovery mode). Next you can install the driver from the repository and use them using menu system -> administration -> hardware drivers or install the previous driver that you used.