Album Art saved to all my tracks instead of one

I recently a few weeks ago embedded my album art on a recently released single I put out. But Now when i open any music file on windows media play the album art fr the single pops up on all my other songs how to i fix it back?

Move every file that should get a separate picture to a separate folder and export the embedded picture to a file called folder.jpg.

how exactly from on mp3 tag

see the FAQs on how to create a folder structure from tags:
/t/8016/1

See the help on how to use an action to export the embedded covers to a file:
https://docs.mp3tag.de/actions/export-cover
Enter as format string: folder
(the .jpg will be added automatically)