Is there some way to delete The Sims 3 account and start out fresh?

You mean on the TS3 site that hosts the store? That would be no, at least not without a real time discussion with Customer Support. There are potentially online transactions associated with store accounts, even if you never made any yourself, that make that kind of account very difficult to rename or merge with another.

I attempted to even change my username and they wouldn't do it. They make things very difficult for some reason.