If you logged-out of iCloud on your iPad - and logged-in using a new/different AppleID, you will not be able to change to a different AppleID account again for 90-days.
If you need help with this, you’ll need to Contact Apple Support. You’ll find the link to Contact Support at top-right of this page.
This limitation, imposed by Apple, is intended to prevent AppleID account abuse. It also worth noting that you should generally only use one AppleID account - as all your App, Service and iTunes purchases are forever tied to the AppleID account from where the purchase is made. You can (and should if needed) update your AppleID account throughout its life, changing your primary and secondary (recovery) email addresses as needed to keep your account up date:
https://appleid.apple.com
Your AppleID account is the key to everything. Neglect (or abuse) this critical account at your peril.
More useful information:
https://support.apple.com/en-us/HT204071
I hope this information is helpful in getting your back onto the right path - and in [eventually] resolving your issue.