[LG G3] I've been stuck on "Firmware Update" and I can't get out... HELP!

[Android Central Question]

I had some problems after rooting my phone with my TWRP version, so I unrooted. I wanted the stock version of my phone back. After trying to restart my phone, it wouldn't reboot anymore. After trying to reverse to stock by KRZ method with the LG Flash Tool, it connected, but got stuck for hours at 5%, and couldnt turn my phone off. I forced it to shut down by yanking out the battery, and tried to flash once more. However, now it just says "Can't connect to server" when flashing. I DONT KNOW WHAT TO DO and I'm very frustrated. Help!