Root at&t HTC One M8 no OS installed

[julmaldo]

So I tried to update my m8 to Marshmallow by flashing a unrooted rom but I deleted my OS by accident and I didn't have a backup. I've tried to search through the forums but haven't found one that has worked for me. Prior to trying to update, I was on KitKat 4.4.4. I can still enter my twrp custom recovery, my bootlader is unlocked, and my M8 is S-off. I am also on mac.
Here are the rest of my variables:
./fastboot getvar all gives me :
(bootloader) version: 0.5
(bootloader) version-bootloader: 3.16.0.0000
(bootloader) version-baseband: 1.16.21331931.LA11G
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main:
(bootloader) version-misc: PVT SHIP S-OFF
(bootloader) serialno: FA46BWM15583
(bootloader) imei: 358718051594674
(bootloader) imei2: Not Support
(bootloader) meid: 00000000000000
(bootloader) product: m8_ul_ca
(bootloader) platform: hTCBmsm8974
(bootloader) modelid: 0P6B17000
(bootloader) cidnum: CWS__001
(bootloader) battery-status: good
(bootloader) battery-voltage: 0mV
(bootloader) partition-layout: Generic
(bootloader) security: off
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT
(bootloader) commitno-bootloader: c3d94491
(bootloader) hbootpreupdate: 11
(bootloader) gencheckpt: 0

Any help is appreciated, Thank you