Regenerated thumbnails

I used this plug in to regenerate my thumbnails to a bigger size. I tried to only do it to a few so I could see the results. I decided it’s better not to and changed the code in functions.php back to the original add_image_size( ‘activello-featured’, 1170, 550, true ); and add_image_size( ‘activello-thumbnail’, 330, 220, true ); were the original code. However, after I saved it back to the original, I went back and then deactivated and deleted the plugin. Now I’m getting 2 pictures in each post of my featured image. I even did a backup and restore of my site but nothing happened. What should I do? Because this is an issue that moved into other themes as well for me.