all email accounts disappeared - now prompting to setup new accounts - 4.4.2 on a galaxy s3

[AC Question]

running 4.4.2 on galaxy s3- gmail app now prompting to set up new accounts, same with youtube, play store and so on, even contacts - all gone (which makes a mess of whatsapp, too)
Mail application again prompts to set up accounts.

any ideas as to why this has suddenly happened?

question is - is there any way to view a log to show the email addresses/passwords that were in use?

any help much appreciated, thanks!