Please uninstall the .run installer using --uninstall option. Then add the Ubuntu graphics ppa and install the driver from that (sudo apt install nvidia-driver-418)
https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa
Then run
grep nvidia /etc/modprobe.d/* /lib/modprobe.d/*
to find the file containing
blacklist nvidia
and remove it. Afterwards, run
sudo update-initramfs -u
and reboot.