Okay - I was stuck in an endless loop of being unable to login to my Apple ID, my Yahoo email suddenly stopped working, Safari only worked on some pages and oddly enough a few of my applications worked just fine like FB. I was stuck in an endless loop of 'Enter your password for your Apple ID'. Verification Failed. I've seen so many error messages relating to Apple ID that I think I could now work there (at least I'd return a call within 24 hrs which is more than I can say for Apple Support - who still has not returned my call).
I tried the wi-fi on/off trick. I tried to off/on the phone - several times. I tried to delete the entire Yahoo profile - couldn't because Find My Phone necessitated that I login with my Apple ID. I tried to delete the email account and to add it back in again to no avail. I would attempt to add in Yahoo and it gave me a brief glimpse of the Yahoo and then simply quit. AOL & Google (which I do not have accounts for...) came up just fine. I tried to add the account using Other. I got through all of it until it error out on SSL. I tried calling Apple Support & they said they'd get back to me soon (that was 4 days ago). I couldn't even delete the iCloud account because of the Find My Phone perpetual loop. I tried syncing my phone to the computer and restoring to a previous backup. It wanted my Apple ID which actually works on my iPad and on my computer - but not in this instance!
I pored over many many many Apple forums to no avail - until this one. Settings -> General-> Reset Network Connections as soon as it reset, I was good to surf & email.
thank you so much