Well, that doesn’t sound too good. 
At first some technical:
- TWP is a custom recovery. Like the name says, it’s for recovery flashing a om is a one way for “recovery”
- Firmware is the name for the rom which comes from he manufacturer
OK, now to your problem:
why do you have tried to flash SuperSu ?? Excuse me, but do you know what rooting is and for what it is needed ? I just have had a discussion about rooting a phone and which risk it is.
I would prefer to start over again with flashstock.bat like described here
If this will work, go this way
- Reboot into TWRP
- Now ONLY tick Dalvik Cache , System , Data and Cache
- After ticking those, Swipe below to wipe
- Once the wipe has completed return to home and select the eOS.zip
- After you selected the zip swipe below to install it
- When all of this is done, reboot into system
And if you really, really, really need root, flash magisk from XDA wen site. But better you will work without rooting