AOL will not load mail on my iPad. Has been working for months and suddenly gives message "wrong username or password"?

Aol suddenly stopped loading mail on my iPad after months of use. Message comes up "username or password incorrect". I did NOT change this and mt email works on my desktop and other apple device. Tried resetting device, syncing device, everything's updated...tried deleting the account and now it will not restore at all. Don't know what else to do. Anyone have a solution?