Really there was no need to flash the custom recovery. Only "boot" into the custom recovery to use the update zip. Doing so this way doesn't overwrite your stock recovery.
You may need to go and flash the stock recovery.img via FASTBOOT command from the link below to restore your stock recovery. First I would reboot your device into your bootloader and then try and go into recovery and see what happens. As far as I know the stock OS update should "overwrite" your custom recovery but that may not apply here to this device.
http://forums.androidcentral.com/sprint-galaxy-nexus/206954-guide-return-stock.html#post2140080
Choose under the first listing "FH05", the RECOVERY file.
Boot into your bootloader, connect via USB and using FASTBOOT do the following.
Code:
fastboot flash recovery recovery.img
Only take a few seconds to complete, when done type...
Code:
fastboot reboot-bootloader
You can then check to see if the stock recovery took. From there just reboot the device when your done or type the following