mobile

I was trying to download the new lollipop OTA and i read that i need to be on stock recovery in order to install the file. So i decided to replace my TWRM with stock recovery. However, when i turn on my phone it just says fastboot mode started and udc commands with a little [number] next to it. I have no idea what to do I am running and LG G2 D800 AT&T. Any help would be greatly appreciated, cause I really effed up big time.