Hi Meenie,

It sounds like you accidentally linked all the worksheets together when you added the two lines to all of them. Don't worry, it's an easy fix!

Here's how to unlink the worksheets:

1. Click on any cell in the worksheet that you want to unlink.
2. Go to the Edit menu and select Links.
3. In the Edit Links dialog box, you should see a list of all the linked worksheets. Select the worksheet that you want to unlink and click on Break Link.
4. Repeat step 3 for any other worksheets that you want to unlink.
5. Click Close to exit the Edit Links dialog box.

Now your worksheets should be unlinked and you can make changes to each one individually without affecting the others.

As for deleting a single worksheet without deleting them all, make sure you are only selecting the sheet tab of the worksheet you want to delete. If you accidentally select multiple sheet tabs, Excel will assume you want to delete all of them. Once you have selected the correct sheet tab, right-click on it and select Delete. This should only delete the selected worksheet.