You lost the beta track at some point, then, as the GM came out a week before the public release of iOS 7. That was a download available from the developer portal, just as beta 1 was. You can't update OTA from a beta to the GM/Public Release, you must do it through iTunes on the computer, just as when you first installed beta 1.
There is no Restore on the phone - only Reset All Content and Settings - and nothing will happen except it will delete everything on your phone. You'll still be on the last beta.
You'll need your computer and iTunes to get off of the betas and onto post-release cycle. And you're going to have to do it soon - the beta you're on expires on October 6.