Primary email account gone

I have had a Yahoo account through Verizon for about 15 years. There are two subaccounts attached to it. Two days ago, the primary account vanished from a tablet I use as my main connection to the internet. Today, it was gone from the backup tablet I mainly use for reading. It is still on my phone, as of now at least. It seems most of the primary account mail is showing up in the subaccount I use the most often. The Add Account link just sends me around in loops.

Also, for the same amount of time, a few but not all of the links I click on, pause at a network redirect page.

Any help would be greatly appreciated. Thanks.