Can anyone help with icloud mail. Mine has been compromised.

Did you revealed account credentials to some one , if the iPad is in your possession convert the account into 2FA Two-factor authentication for Apple ID - Apple Support

Read If you think your Apple ID has been compromised - Apple Support

Either iPad files is corrupted or mail application remove mail account and once again add Add and remove email accounts on iPad - Apple Support

Last option if iPad is corrupted erase it and reinstall How to factory reset your iPhone, iPad, or iPod touch - Apple Support

How to erase all content and settings - Apple Support

Erase iPad - Apple Support