Media Library How to correct attached to

I have created a blog for an artist. So far, the blog contains 14 pictures. There is one post for each picture.
There are three options for displaying a picture when it is clicked on and the one my client wants is for it to display by itself

When adding his pictures to his posts, he didn’t know what to do for a link url because he didn’t understand “Enter a link URL or click above for presets.” So he left it blank.

Now, though, when you go to the media library page and look at the images, they are all showing up as attached to the first blog post containing a picture.

I opened the media library, by clicking on it above the editor and saw that these links were all garbled but indeed all began with that post link.

I attempted to correct the links by showing each picture and fixing them, then saving changes but the changes were not saved.

So I clicked on the picture in each post and clicked on the current link button. This had no effect on the Attached to field in the gallery listing.

I went to the mysql database to try to see where these attachments were coming from but I all I could see this listing.

Whenever you click on a picture in the gallery, instead of taking you to the post that is about that picture, it displays the picture with a link back to the first post.

In order to fix this I had to delete that post so that the images were showing attached to nothing and then go back and delete and re-enter the image in each post.

There has to be an easier way!!