Not to add to your dissapointment, frustration and anger, but if you had this many images on your iPad, you should have made some efforts long ago to store copies of these images elsewhere.
If you never backed up all your images by transferring them to a photos app on a Mac or a PC, through saving photos in iTunes on a computer and backing up in iTunes on a computer, backing up your images onto iCloud OR to local external storage devices made for mobile devices, you needed to do this and before now when something detrimental, like this, has happened to your important and precious data.
This is why you need to have some method and/or more robust and stable hardware to periodically save your mobile device data to.
A mobile computing device is NOT a permanent place to your store important data to.
These devices are not as stable and robust enough as a full blown laptop or desktop computer to trust for ANY long-term data storage.
You need to have, at least, one other more robust and reliable source to store your important and precious data and images that you never want to lose.
Even on a more robust computer, you need to have/should have a backup of your important data on your computer, that you never want to lose, in case of hard drive failure or some other computer failure.
FYI, cloud storage is fine, still much better to save to a local source like a computer or WiFi enabled portable and external hard drives designed to use with mobile devices.
These are available from Seagate or Western Digital and there is even a new WiFi enabled USB Flash drive from SanDisk called the SanDisk Connect that comes in a variety of storage sizes that works with any iDevice and you can transfer and store data on this flash drive wirelessly.
Sorry & Good Luck with all of this in the future.