responded to 'NEXT OF KIN'

I received a email from Barrister Williams asking me to be next of kin to a deceased man who had deposited 3.5 million dollars U.S.in a nigerian bank account at the International bank of London. He asked if I could write a letter to the bank claiming to be the next of kin, and give the bank this info. I did this. He gave me 4 forms one was a death certificate, His passport, The orignial deposite to the bank from the deceased,and some other one. He also wrote what I was to re-write and send to the bank.Then he called me one day I accidently hung up on him he sent me a E-mail saying How rude that was and how I will remain poor. Then I get this email from the bank asking for some other form that I never had and giving me 48 hours to produce it or I would be expidited to London to be charged with defrauding a bank. If I try to email Barrister Williams its instantly returned non-deliverable. Can I be brought to stand trial for this? What should I do now. Was this one of those 419 scams? I have no money in the bank account that I gave to them,I have bad credit can they still steal my idenity? Are the attachments I received from Williams real?