Nope. I've committed similar errors before and the phone did not break.

Can you give me a screenshot? Or do you have IM (e.g. Yahoo Messenger)? My username is topet2k12001.

Try this:

1. Disconnect the phone from the USB
2. Press and hold the "U" key on your N900 keyboard
3. Attach the USB adapter. You should see a USB logo at the top-right of your N900's screen
4. The flasher should automatically continue after a few seconds. DO NOT RELEASE THE "U" KEY UNTIL YOU SEE THE FLASHER CONTINUE.

If not...

4. While holding the "U" key, enter the Step 2 command again (just press the up arrow on your computer's keyboard; the command line stores a history of previous commands that you have typed). Keep on holding the "U" key, and press Enter on your computer's keyboard.