I'm assuming you were using an ICS ROM, which requires a partition on the SD card to function. Gingerbread ROMs work fine without the SD card. You need to do a fresh ROM install.
You'll have to download a ROM with a computer and put it on the SD card. There's an option in recovery, usually in the mounts & storage section, to mount the SD card. This will allow you to copy files to the SD card over USB.