Question: How do I remove the effects of identity fraud from my credit? How long will it take to clear up?

Question : How do I remove the effects of identity fraud from my credit? How long will it take to clear up?
Before I left the country for work, I stored a lot of my personal papers at my grandma's house, including bank and tax records with my SSN and DOB. One of her former home health care workers opened several credit accounts in my grandmother's name, and on almost all of them she used my SSN to name me an "authorized user" which meant that she had a card to play with and so did her sister. They've charged up about $78,000 work of stuff that we know about ranging from platinum cards from Chase to Gateway computers, Cingular Wireless accounts, Home Depot and Nordstrom charge accounts.The only way my grandma and dad found out about this is that several collection and credit companies were harassing her about accounts she's never heard of. She's 84 and senile. I had no idea until I got back that I am also being pursued for these debts. The nurse aide went so far as to put in a change of address for me through the post office so I never EVER saw a statement or bill.What should I do???My credit is in shambles now, but it was PRISTINE before all of this. My dad is working on clearing my grandmother in all of this with the credit bureaus, using the police report(s), but what should I do about my own? Do I need to send letters to the three reporting agencies with copies of the reports explaining the fraud? HELP!All of my plans have been totally put on ice because of this. I had planned on buying a house and now I'm scared my employer will run a credit report and be all "Heeeey, she can't work for us anymore! Look at that FICO! Ew!"
- asked by Jena