How do I get a user name back after I deleted my account?

How do I get a user name back after I deleted my account? I opened an account w/the user name as lantz45. I deleted this account thinking that I could get my name back. "Sorry Charlie, no cigar". I am now very sad. lantz45 is my identity. It is my name. I need it to go on. Please help me get it back! Thanks! I love you all!!