Failed rooting attempt made my phone unable to perform system update.

I was being stupid a while ago and tried to root my phone, and now every time I tried to update the system(currently 4.4.2) I was shown the boot menu with the TEMPERED tag on the top. I've tried re-lock the bootloader but most utilities out there requires my phone to be S-off, sadly mine is still S-on. Are there any ways to fix this?