Regenerating images does not work simply because the images are based on the initial image upload (original product image) that is also linked to the product ID that it is uploaded for.
You have the mapping of image and product id in the ps_image table, but unfortunately you have changed the original product IDs that the mappings are based on.
Do you have some backup of the previous db? If not, you cannot solve too much.
If you have managed hosting ask their support if they have a database backup for your domain.