Not quite, the method you have mentioned above will restore the iPhone to the latest firmware and baseband, and loose the unlock.
OP:
Before you do anything, try this.
Download Tiny Umbrella from the following website.
http://cache.firmwareumbrella.com/downloads/tinyumbrella-4.1.13.exe
Then put your iPhone into DFU mode, connect your phone to your computer.(Close iTunes if it opens).
Now open Tiny Umbrella and click the highlighted button to kick the phone out the boot loop.(click Save My SHSH before doing this though).
Hopefully it will fix the iPhone.
Otherwise you will have to restore your iPhone(more details on that later).