Restore Android 6 on Moto G (2nd Gen) without adb? After trying to root my Moto G (xt1068) and getting stuck in a boot loop, I tried to restore a functioning version of Android and I got stuck in the middle with a re-locked bootloader because I followed an instruction online that seemed to work for some people (...).
So, now the bootloader is locked, the device only boots into fastboot, and has no proper system image installed right now. I cannot access adb because I cannot re-activate USB debugging. Is there any way at all to get this one back to work or did I completely destroy it? I can look up the link to the advice I followed for 'restoring' my device, if that helps.
I am using a Mac but I have access to a Windows 7 PC if necessary. Any advice or help would be highly appreciated, thanks in advance!
EDIT 29.10.16:
I have found a German version of the Moto G (2014) Marshmallow stock ROM, but it still does not solve the problem. The version is

titan_retde-user 6.0 MPB24.65-34 31 release-keysMSM8626BP_1032.3116.99.00R

Upon trying to flash boot or recovery, the phone itself says &quot;version downgraded for recovery&quot; and the terminal gives me the following result:

target max-sparse-size: 256MB
sending 'recovery' (10280 KB)...
OKAY [  0.349s]
writing 'recovery'...
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.772s

Does that mean that the version I tried was also not the current one? I was not aware that there was anything newer than Android 6.0 for the Moto G, but I will look for more possible ROMs to try. If you have any further advice, I would definitely appreciate it!
Older Update:
I had initially used TWRP in the unlocking/rooting process, and it used to work when I first got stuck in the boot loop. Now, I tried 'fastboot boot twrp.img', which did not work ' FAILED (remote failure)', and I tried flashing TWRP again by using ' fastboot flash recovery twrp.img' and I got the following response in terminal:
(bootloader) has-slot:recovery: not found
target reported max download size of 536870912 bytes
sending 'recovery' (8092 KB)...
OKAY [  0.294s]
writing 'recovery'...
(bootloader) Battery Low!!
FAILED (remote failure)
finished. total time: 0.343s
This did not work, as pointed out below. I then tried the further suggestion to flash the bootloader and the gpt. I used the following commands:

fastboot flash partition gpt.bin
fastboot flash motoboot motoboot.img
fastboot flash logo logo.bin
fastboot flash boot boot.img

Upon the last command, I got the following error message:

(bootloader) has-slot:boot: not found
target reported max download size of 536870912 bytes
sending 'boot' (10200 KB)...
OKAY [  0.342s]
writing 'boot'...
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.781s

The device screen gave me this information:

getvar:has-slot-boot
getvar:partition-type:boot
getvar-max-download-size
download:009£6000
flash:boot
hab check failed for boot
failed to verify hab image boot

Does any of that make sense? I am using the following version of the software:

SW Version: titan_retbr_ds-user 6.0 MPB24.65-34-3 3 release-keysMSM8626BP_1032.3116.99.00R

EDIT:
I tried another version of the Android 6.0 stock image (I got this one through the xda link: http://forum.xda-developers.com/moto-g-2014/general/official-stock-firmware-t3018682) and I got the same result:

SW Version: titan_retbr_ds-user 6.0 MPB24.65-34 32 release-keysMSM8626BP_1032.3116.99.00R

I thought this was the most current version, isn't it? I had updated to Marshmallow when the update was available, and (if that is pertinent info) I have a German Moto G.
The solution was to re-open the bootloader. It is possible to unlock it again by using the code provided by Motorola and the same command I used for unlocking the bootloader in the first place. I did not know it was possible to do that until a friendly person pointed it out to me. After that, I was able to (almost) effortlessly flash a stock ROM, and then (just for trying how it works) CyanogenMod 13.

Thanks for your assistance on this!