Do you have GNM's custom recovery installed?
If yes, using adb reboot into recovery using the adb wait-for-device reboot recovery command during the boot loop. Once in recovery restore the nandroid you should have made before you started messing with the phone's file structure. If you don't have one ask around for someone to send you their's.
If not, I don't think there will be much you can do to fix it. The phone does not have a working recovery (at least one us mear mortals can use) and once it's bricked there is not much you can do.
Are you the original owner?
If yes, then it is still under warranty. Be vague, answer direct questions with things like "What does that mean" and "I don't know, it was like this when I woke up this morning", and other similar answers. Never tell how you rooted it, or were using titanium backup, or anything else like that.
The down side is the replacement you get will be running the dreaded M100 build that right now means no root.
If that is not an option, and you like the phone, there are bunches of them on eBay. Craigslist can be a source for these too.
Sorry for your luck, but I have been there and done that and paid for it.