Problem with simple database on restaurant site - repost

I have a problem with a restaurant site and the database. It is a simple custom made cms. I'm trying to add a new menu or delete a menu but it keeps conflicting with old items in the menu. For example. I want to add a new Sushi menu. I delete the old sushi menu but it keeps coming back and interferring with the new menu. It is not possible for me to make a subcategory to the sushi menu if that subcategory is called the same as a main category. I need you to fix the database and cms so I can add and delete menu's without the database conflicting. I need to be able to make sub menus that have identical names to main menus. I will show site and backend to interested bidders. I need this done right away.