mobile

Hi, I wanted to return my g2 to stock rom because I didn't like my custom rom, so I followed the lg flash tool guide(tot):http://forum.xda-developers.com/show....php?t=2432476
It worked, but it was jelly bean 4.2 instead of Kit kat 4.4, so I tried to install TWRP so that I can install again a custom rom, but when I tried to backup before flashing TWRP, it wrote "backup Failed", I tried again and it wrote it again, but then the phone just stayed on the boot animation for a few seconds and didnt turn on again. After that, again I tried to do the flash tool method just to return to stock rom but now, it just doesn't work, whenever I insert the DLL and TOT file and start the installation, it goes up to 80% extremely quick and just boots up to TWRP without actually installing the stock rom. So now I'm stuck here with TWRP but without a system to boot to and no rom on my sd card to flash.

I really need help here because I have no idea how to continue.

Thanks for any help!