*The only way back in is through recovery mode. This process will wipe your iOS device, unless you've synced it to iTunes before you won't be able to create a backup prior to starting the process*
First you have to make sure that your iTunes is up to date with the latest version on the computer you're using (I think 12.5.5)
Once you've ensured the latest iTunes is uploaded you can begin.
With iTunes closed, connect your iPad to your computer.
Open iTunes if it didn't open automatically. Once iTunes is opened hold down the home button and sleep/wake button simultaneously until you see an iTunes icon appear with a USB pointing up on your iPad.
Once that appears, you should see a pop up appear on your iTunes program with two options "restore" or "update" you can choose restore and then allow iTunes to restore your iPad.
When the process is finished you can eject your iPad thru iTunes and set it up as a new iPad without being prompted to enter a password.
Hope it works out for you, good luck!
You can check your backups on your computer or iCloud too, you may have some saved!