When you boot into safe mode, Windows runs on basic drivers, so there would be no nvidia apps. While in safe mode you can uninstall the drivers from the Control Panel; Programs and Features. You should also delete C:\nvidia, or Windows will just reload the drivers that may be casuing your problem. This should allow you to boot into Windows and you can try and install you nvidia drivers again.
You should use the drivers from Asus.
https://www.asus.com/us/Laptops/ASUS-TUF-Gaming-FX505/HelpDesk_Download/