Help with a /system partition being deleted during TWRP update?

I've looked on the forums and can't find a solution. So I attempted to flash a TWRP img file inside TWRP to the recovery partition, which i probably shouldn't have done. It killed the recovery, So I've been in Heimdall via Cyanogenmods instructions to get my boot and Aboot files right after I killed those somehow. I haven't changed up those files since I've gotten the phone, and I've not taken any OTA's, so I thought those files were the same since it's the same instructions I used previously. I can get the new TWRP up, but i've deleted my /system partition somehow. TWRP tells me it cannot mount it, then tells me it doesn't exist. I'm still under the impression that i'm on an unlocked bootloader. The Cyanogenmod 12 load screen is still there before Teamwin pops up, and I can get into download mode. I don't know if she's still rooted, as I have no OS installed. What avenue should I pursue to get it working with any ROM? I miss having root, as that makes this stuff gravy when in ADB. Should I take a look with Casual or find some ODIN exe that hopefully isn't just malware? I have used Casual root on it in the past, that worked for quite awhile.

Thanks a bunch guys.