Updated to ios 9 now it says email address entered does not match your account for yahoo mail.

Last night I updated to ios 9 on my iphone 6 plus. Everything seemed ok until I tried to use my yahoo email. It asked for my password which I entered immediately and then it came back saying that the email address entered does not match your account.

I clicked onto the link to try to get access to my email, changed password on both my computer (which is working just fine, no problems signing into yahoo) and still it didn't work. I've tried numerous times today and still no joy. I don't know what else I can do. I don't even know if you can revert back to before the update as you would do on a pc.

Can anyone help please?