Christ, hell of a bug. When you were uninstalling the mod you may have deleted a essential file for GTA V. I don't quite know what you would've deleted, but whatever it was made your system go . I would suggest a complete re installation of GTA and use the mods folder next time so this doesn't happen again. You could create a folder on your desktop and drag and drop some of the non messed up mods and dump them in there so you don't have to go back and re install everything.