contact steam man, thats the only way you shall get out of this. I'm guessing if they are not replying to you is that it happened to a bunch of people and they currently have a work overflow in the department that handles these things. What's the time frame between your emails to them?
Also, check around their forums, maybe you're not alone.
Also, as a preparatory measure find all the emails you got as confirmation from game purchases on steam, in case they can't restore your old account you'll be able to ask them to just make a new account with all the games you had.