Can't enter recovery or update: boot certification verify error

I am on 6.0.1 CyanogenMod13. I haven't done a whole lot root-wise but just today I was looking to get something from xposed and it turned out I didn't even have it installed, so I downloaded it and installed it but needing to flash the .zip I tried to boot into TWRP recovery. Somehow it got uninstalled or something because I could only get into the LG stock screen asking if I wanted to wipe everything. So I tried to install TWRP using Flashify, I installed and on the reboot it gave me a "Can't Enter Recovery Or Update" and some more things about it on the top left above the boot logo. I can't do anything recovery-wise. I'm looking to sell my G2 but I want to make it stock or at least a clean install and I can't do any of that. What can I do??