Be careful when you advise people to use erase all!!!!
OP did not say if he is jailbroken or not, if he is and he does erase all he has to restore to iOS 6.0 to get out of the boot loop.
@OP
No you cannot re-restore to 5.1.1 without blobs.
You are stuck on 5.1.1 which you can jailbreak
or update to iOS6 and are than stuck there without a jailbreak (for now).