How do I root my device without twrp???
Oh I thought you could boot to it but it doesn't stick
If you can't get into twrp at all it's user error
Follow my guide on the twrp thread
Make sure you rename the image recovery.img
Put your phone into fastboot mode - hold Vol down & power button
Then in a cmd prompt where you have recovery.img & fastboot type
fastboot flash recovery recovery.img
Then use the volume keys to select recovery and press power button to select
Post your cmd output but it should say write OK at the end
Ignore the error is not signed or corrupt that comes before that
Obviously I presume you have already unlocked your bootloader - just follow all the instructions on the twrp thread
Also you don't reboot the phone between flashing twrp and entering twrp for the first time