Do not panic. It is a real easy fix. Boot into recovery, you may have to pull the battery for 30 secs, put it back in and power on while holding x (for droid 1, and 2). While in recovery restore your nandroid backup. If you do not have a nandroid backup. Install a rom through your recovery menu (if you used RM you should be in CW recovery so the instructions below are for cw recovery) .
To install a rom through recovery:
Click partitions menu
- hook you droid to your computer or laptop using your usb cord
- Click mount USB storage
your phone's sdcard should come up on your computer (is not power off remove sd card and put it in your computer's sd card slot)
- Install a rom (any rom) from here: Custom Roms - Droid Forum - Verizon Droid & the Motorola Droid Forum
after you get it on your sdcard make sure the rom is on the root of your sdcard, that means it does not go into any folders. (no need to rename it)
-click power to back up one screen
- click install zip from sdcard (and find the rom that you placed on your sdcard)
- allow rom to install
-power back to the main menu and wipe data and cahce
- then reboot.
If you need a video and some basic knowledge about installing roms through recovery, please see here: What you need to know about rooting:
And for all other CW related issues see this troubleshooting guide: Troubleshooting guides/Clockwork recovery guide