You will need Staff help and I have flagged this thread for their attention. In order to help you get access to your blog Staff need one of the following things in order to correctly identify you as the blog owner:
1. an email from the email address associated with the account or revealing what that associated email address was
2. the wordpress.com API key for your account. This was included in your welcome email with a note to keep it safe. Please do not post the API key here.
3. if you have purchased any upgrades for the blog a transaction number send it to the email address
Do you have access to any of those three?