At first glance I have two questions that come to mind.
First, why are you using the query SELECT * (asterisk gives ALL values) if you want ONLY values for a specific user?
Perhaps, SELECT item, next item, etc WHERE username = $username would be more defining. (You can research "php select where" for better understanding)
Also, I don't see anywhere that you are specifying which user's information you want displayed.
Maybe I missed something, but I hope this is helpful.