@emmasmith075 , ok here's how to reset the game and get your Neighborhoods back.
Locate your Sims 2 folder (found Documents > EA Games > Sims 2). Move that folder to your Desktop. Do not copy and paste or create a shortcut. Actually move the folder. Don't worry the contents will be safe. Next, start up your game to allow for a new folder to generate. Start a new game (just to make sure the game runs as it should) remembering that none of your saved games, CC or mods will be present. You can either save the game or simply exit. At this point, I just want to make sure you can play the game ok without other issues.
Next, open up the folder on your Desktop and the same folder in your Documents folder so you have two windows open showing the contents of both folders. You shouldn't need to transfer the contents from the following folders: Cameras, Config, LockedBins, Movies, Music (unless you have custom music in your files), SC4 Terrains, and Thumnails. These are mostly games files and you shouldn't need to transfer the contents. You should be able to simply move your Downloads and Teleport folders from the Desktop folder to your new game folder in Documents.
Now that you have the two windows opens, here comes the fun part. Starting with the Collections folder (just going alphabetically) open up the folder from your Desktop and open the same folder in your game folder. Either copy or simply move the contents of the folder from the Desktop to the game folder. This way the game will recognize the folder and the content will show in your game. Do the same for each folder except Neighborhoods. These are a bit more tricky. Because each 'Hood has multiple nested files, you'll need to transfer the contents for each file.
I know this sounds like a lot to do, but this way your game will recognize your saved games.
Please keep me updated.