i had wallet on blocrkchain and all my wallet details was saved in my gmail folder like identifier password and wallet address etc. so to login to my wallet i always used to login to my email first. and also i signup with same email for localbitcoins.
I am not familiar with"blocrkchain". Do you mean blockchain.info or the blockchain? They are not the same. Saying "blockchain" is ambiguous and makes a difference about losing private keys or blockchain.info account info.
Sorry for the loss, but not much you can do.