One suggestion? Don't mod or root your new phone the first day, you MUST use it for minimum two week with stock rom LG. ( according to me )
But getting back to your question, I also had your same problem. And I solved with LG's Launcher (computer program), I made a reset using a KDZ already downloaded.
Download The Appropriate Firmware file and Extract the zip, if required. Download and install LG support Tool.
Download and install LG Flash Tool. Download LG G2 USB Drivers if you need. Turn off your LG G2 and boot into Download Mode, press and Hold Volume Up Key and Plug in the USB Cable. Extract the LG Flash Tool and double click the UpTestEX.exe
Once the Flash Tool is Open, Change the select type to 3GQCT*and change the phone mode to DIAG. Click the select KDZ option file and select the .KDz extention file from the downloaded firmware folder.
Click Normal Web Upgrade Test. Now wait a moment and you will see a pop-up window, showing you the phone information. Click Upgrade Start Button. After a few seconds, there will be another pop-up asking you the Language and Country. As country, Select Republic Of Korea and Language English. Finally click OK to proceed the installation. When the Flashing is done, your LG G2 will reboot, donít forget to do a Factory Reset. To do it, press and Hold Volume Down + Power Buttons until you see the Phone screen.
Try. Good luck