Ok : Dont panic.
Follow The 3rd Guide on the main POST
3. How to Install a ROM using Clockwork Manually
You will have to Re-install the ROM from the SDCard
You can mount the SDCard in Clockwork by going into Mounts (near bottom of Menu) then choose the last one Mount USB
Then Choose the Install from SDCard (choose Zip) and choose the ROM you want (off your SD Card)
Then Choose wipe cache partition & then wipe data/factory reset. (both from main menu)
After that re-boot and wait for about 6 minutes (if you don't get stuck on the green android).
If you do get stuck again, then is is likely that you need to re-download the ROM file as the one you have is damaged.
If you can get into Clockwork - then you are NEVER unable to recover.